parts of an abstract in a research paper

Writing an Abstract for Your Research Paper

Definition and Purpose of Abstracts

An abstract is a short summary of your (published or unpublished) research paper, usually about a paragraph (c. 6-7 sentences, 150-250 words) long. A well-written abstract serves multiple purposes:

• an abstract lets readers get the gist or essence of your paper or article quickly, in order to decide whether to read the full paper;
• an abstract prepares readers to follow the detailed information, analyses, and arguments in your full paper;
• and, later, an abstract helps readers remember key points from your paper.

It’s also worth remembering that search engines and bibliographic databases use abstracts, as well as the title, to identify key terms for indexing your published paper. So what you include in your abstract and in your title are crucial for helping other researchers find your paper or article.

If you are writing an abstract for a course paper, your professor may give you specific guidelines for what to include and how to organize your abstract. Similarly, academic journals often have specific requirements for abstracts. So in addition to following the advice on this page, you should be sure to look for and follow any guidelines from the course or journal you’re writing for.

The Contents of an Abstract

Abstracts contain most of the following kinds of information in brief form. The body of your paper will, of course, develop and explain these ideas much more fully. As you will see in the samples below, the proportion of your abstract that you devote to each kind of information—and the sequence of that information—will vary, depending on the nature and genre of the paper that you are summarizing in your abstract. And in some cases, some of this information is implied, rather than stated explicitly. The Publication Manual of the American Psychological Association , which is widely used in the social sciences, gives specific guidelines for what to include in the abstract for different kinds of papers—for empirical studies, literature reviews or meta-analyses, theoretical papers, methodological papers, and case studies.

Here are the typical kinds of information found in most abstracts:

• the context or background information for your research; the general topic under study; the specific topic of your research
• the central questions or statement of the problem your research addresses
• what’s already known about this question, what previous research has done or shown
• the main reason(s) , the exigency, the rationale , the goals for your research—Why is it important to address these questions? Are you, for example, examining a new topic? Why is that topic worth examining? Are you filling a gap in previous research? Applying new methods to take a fresh look at existing ideas or data? Resolving a dispute within the literature in your field? . . .
• your research and/or analytical methods
• your main findings , results , or arguments
• the significance or implications of your findings or arguments.

Your abstract should be intelligible on its own, without a reader’s having to read your entire paper. And in an abstract, you usually do not cite references—most of your abstract will describe what you have studied in your research and what you have found and what you argue in your paper. In the body of your paper, you will cite the specific literature that informs your research.

When to Write Your Abstract

Although you might be tempted to write your abstract first because it will appear as the very first part of your paper, it’s a good idea to wait to write your abstract until after you’ve drafted your full paper, so that you know what you’re summarizing.

What follows are some sample abstracts in published papers or articles, all written by faculty at UW-Madison who come from a variety of disciplines. We have annotated these samples to help you see the work that these authors are doing within their abstracts.

Choosing Verb Tenses within Your Abstract

The social science sample (Sample 1) below uses the present tense to describe general facts and interpretations that have been and are currently true, including the prevailing explanation for the social phenomenon under study. That abstract also uses the present tense to describe the methods, the findings, the arguments, and the implications of the findings from their new research study. The authors use the past tense to describe previous research.

The humanities sample (Sample 2) below uses the past tense to describe completed events in the past (the texts created in the pulp fiction industry in the 1970s and 80s) and uses the present tense to describe what is happening in those texts, to explain the significance or meaning of those texts, and to describe the arguments presented in the article.

The science samples (Samples 3 and 4) below use the past tense to describe what previous research studies have done and the research the authors have conducted, the methods they have followed, and what they have found. In their rationale or justification for their research (what remains to be done), they use the present tense. They also use the present tense to introduce their study (in Sample 3, “Here we report . . .”) and to explain the significance of their study (In Sample 3, This reprogramming . . . “provides a scalable cell source for. . .”).

Sample Abstract 1

From the social sciences.

Reporting new findings about the reasons for increasing economic homogamy among spouses

Gonalons-Pons, Pilar, and Christine R. Schwartz. “Trends in Economic Homogamy: Changes in Assortative Mating or the Division of Labor in Marriage?” Demography , vol. 54, no. 3, 2017, pp. 985-1005.

Sample Abstract 2

From the humanities.

Analyzing underground pulp fiction publications in Tanzania, this article makes an argument about the cultural significance of those publications

Emily Callaci. “Street Textuality: Socialism, Masculinity, and Urban Belonging in Tanzania’s Pulp Fiction Publishing Industry, 1975-1985.” Comparative Studies in Society and History , vol. 59, no. 1, 2017, pp. 183-210.

Sample Abstract/Summary 3

From the sciences.

Reporting a new method for reprogramming adult mouse fibroblasts into induced cardiac progenitor cells

Lalit, Pratik A., Max R. Salick, Daryl O. Nelson, Jayne M. Squirrell, Christina M. Shafer, Neel G. Patel, Imaan Saeed, Eric G. Schmuck, Yogananda S. Markandeya, Rachel Wong, Martin R. Lea, Kevin W. Eliceiri, Timothy A. Hacker, Wendy C. Crone, Michael Kyba, Daniel J. Garry, Ron Stewart, James A. Thomson, Karen M. Downs, Gary E. Lyons, and Timothy J. Kamp. “Lineage Reprogramming of Fibroblasts into Proliferative Induced Cardiac Progenitor Cells by Defined Factors.” Cell Stem Cell , vol. 18, 2016, pp. 354-367.

Sample Abstract 4, a Structured Abstract

Reporting results about the effectiveness of antibiotic therapy in managing acute bacterial sinusitis, from a rigorously controlled study

Note: This journal requires authors to organize their abstract into four specific sections, with strict word limits. Because the headings for this structured abstract are self-explanatory, we have chosen not to add annotations to this sample abstract.

Wald, Ellen R., David Nash, and Jens Eickhoff. “Effectiveness of Amoxicillin/Clavulanate Potassium in the Treatment of Acute Bacterial Sinusitis in Children.” Pediatrics , vol. 124, no. 1, 2009, pp. 9-15.

“OBJECTIVE: The role of antibiotic therapy in managing acute bacterial sinusitis (ABS) in children is controversial. The purpose of this study was to determine the effectiveness of high-dose amoxicillin/potassium clavulanate in the treatment of children diagnosed with ABS.

METHODS : This was a randomized, double-blind, placebo-controlled study. Children 1 to 10 years of age with a clinical presentation compatible with ABS were eligible for participation. Patients were stratified according to age (<6 or ≥6 years) and clinical severity and randomly assigned to receive either amoxicillin (90 mg/kg) with potassium clavulanate (6.4 mg/kg) or placebo. A symptom survey was performed on days 0, 1, 2, 3, 5, 7, 10, 20, and 30. Patients were examined on day 14. Children’s conditions were rated as cured, improved, or failed according to scoring rules.

RESULTS: Two thousand one hundred thirty-five children with respiratory complaints were screened for enrollment; 139 (6.5%) had ABS. Fifty-eight patients were enrolled, and 56 were randomly assigned. The mean age was 6630 months. Fifty (89%) patients presented with persistent symptoms, and 6 (11%) presented with nonpersistent symptoms. In 24 (43%) children, the illness was classified as mild, whereas in the remaining 32 (57%) children it was severe. Of the 28 children who received the antibiotic, 14 (50%) were cured, 4 (14%) were improved, 4(14%) experienced treatment failure, and 6 (21%) withdrew. Of the 28children who received placebo, 4 (14%) were cured, 5 (18%) improved, and 19 (68%) experienced treatment failure. Children receiving the antibiotic were more likely to be cured (50% vs 14%) and less likely to have treatment failure (14% vs 68%) than children receiving the placebo.

CONCLUSIONS : ABS is a common complication of viral upper respiratory infections. Amoxicillin/potassium clavulanate results in significantly more cures and fewer failures than placebo, according to parental report of time to resolution.” (9)

Some Excellent Advice about Writing Abstracts for Basic Science Research Papers, by Professor Adriano Aguzzi from the Institute of Neuropathology at the University of Zurich:

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APA Abstract (2020) | Formatting, Length, and Keywords

Published on November 6, 2020 by Raimo Streefkerk . Revised on January 17, 2024.

An APA abstract is a comprehensive summary of your paper in which you briefly address the research problem , hypotheses , methods , results , and implications of your research. It’s placed on a separate page right after the title page and is usually no longer than 250 words.

Most professional papers that are submitted for publication require an abstract. Student papers typically don’t need an abstract, unless instructed otherwise.

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Table of contents

How to format the abstract, how to write an apa abstract, which keywords to use, frequently asked questions, apa abstract example.

Formatting instructions

Follow these five steps to format your abstract in APA Style:

• Insert a running head (for a professional paper—not needed for a student paper) and page number.
• Set page margins to 1 inch (2.54 cm).
• Write “Abstract” (bold and centered) at the top of the page.
• Do not indent the first line.
• Double-space the text.
• Use a legible font like Times New Roman (12 pt.).
• Limit the length to 250 words.
• Indent the first line 0.5 inches.
• Write the label “Keywords:” (italicized).
• Write keywords in lowercase letters.
• Separate keywords with commas.
• Do not use a period after the keywords.

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The abstract is a self-contained piece of text that informs the reader what your research is about. It’s best to write the abstract after you’re finished with the rest of your paper.

The questions below may help structure your abstract. Try answering them in one to three sentences each.

• What is the problem? Outline the objective, research questions , and/or hypotheses .
• What has been done? Explain your research methods .
• What did you discover? Summarize the key findings and conclusions .
• What do the findings mean? Summarize the discussion and recommendations .

Check out our guide on how to write an abstract for more guidance and an annotated example.

Guide: writing an abstract

At the end of the abstract, you may include a few keywords that will be used for indexing if your paper is published on a database. Listing your keywords will help other researchers find your work.

Choosing relevant keywords is essential. Try to identify keywords that address your topic, method, or population. APA recommends including three to five keywords.

An abstract is a concise summary of an academic text (such as a journal article or dissertation ). It serves two main purposes:

• To help potential readers determine the relevance of your paper for their own research.
• To communicate your key findings to those who don’t have time to read the whole paper.

Abstracts are often indexed along with keywords on academic databases, so they make your work more easily findable. Since the abstract is the first thing any reader sees, it’s important that it clearly and accurately summarizes the contents of your paper.

An APA abstract is around 150–250 words long. However, always check your target journal’s guidelines and don’t exceed the specified word count.

In an APA Style paper , the abstract is placed on a separate page after the title page (page 2).

Avoid citing sources in your abstract . There are two reasons for this:

• The abstract should focus on your original research, not on the work of others.
• The abstract should be self-contained and fully understandable without reference to other sources.

There are some circumstances where you might need to mention other sources in an abstract: for example, if your research responds directly to another study or focuses on the work of a single theorist. In general, though, don’t include citations unless absolutely necessary.

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.

Streefkerk, R. (2024, January 17). APA Abstract (2020) | Formatting, Length, and Keywords. Scribbr. Retrieved September 3, 2024, from https://www.scribbr.com/apa-style/apa-abstract/

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Home » Research Paper Abstract – Writing Guide and Examples

Research Paper Abstract – Writing Guide and Examples

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Research Paper Abstract

Research Paper Abstract is a brief summary of a research pape r that describes the study’s purpose, methods, findings, and conclusions . It is often the first section of the paper that readers encounter, and its purpose is to provide a concise and accurate overview of the paper’s content. The typical length of an abstract is usually around 150-250 words, and it should be written in a concise and clear manner.

Research Paper Abstract Structure

The structure of a research paper abstract usually includes the following elements:

• Background or Introduction: Briefly describe the problem or research question that the study addresses.
• Methods : Explain the methodology used to conduct the study, including the participants, materials, and procedures.
• Results : Summarize the main findings of the study, including statistical analyses and key outcomes.
• Conclusions : Discuss the implications of the study’s findings and their significance for the field, as well as any limitations or future directions for research.
• Keywords : List a few keywords that describe the main topics or themes of the research.

How to Write Research Paper Abstract

Here are the steps to follow when writing a research paper abstract:

• Start by reading your paper: Before you write an abstract, you should have a complete understanding of your paper. Read through the paper carefully, making sure you understand the purpose, methods, results, and conclusions.
• Identify the key components : Identify the key components of your paper, such as the research question, methods used, results obtained, and conclusion reached.
• Write a draft: Write a draft of your abstract, using concise and clear language. Make sure to include all the important information, but keep it short and to the point. A good rule of thumb is to keep your abstract between 150-250 words.
• Use clear and concise language : Use clear and concise language to explain the purpose of your study, the methods used, the results obtained, and the conclusions drawn.
• Emphasize your findings: Emphasize your findings in the abstract, highlighting the key results and the significance of your study.
• Revise and edit: Once you have a draft, revise and edit it to ensure that it is clear, concise, and free from errors.
• Check the formatting: Finally, check the formatting of your abstract to make sure it meets the requirements of the journal or conference where you plan to submit it.

Research Paper Abstract Examples

Research Paper Abstract Examples could be following:

Title : “The Effectiveness of Cognitive-Behavioral Therapy for Treating Anxiety Disorders: A Meta-Analysis”

Abstract : This meta-analysis examines the effectiveness of cognitive-behavioral therapy (CBT) in treating anxiety disorders. Through the analysis of 20 randomized controlled trials, we found that CBT is a highly effective treatment for anxiety disorders, with large effect sizes across a range of anxiety disorders, including generalized anxiety disorder, panic disorder, and social anxiety disorder. Our findings support the use of CBT as a first-line treatment for anxiety disorders and highlight the importance of further research to identify the mechanisms underlying its effectiveness.

Title : “Exploring the Role of Parental Involvement in Children’s Education: A Qualitative Study”

Abstract : This qualitative study explores the role of parental involvement in children’s education. Through in-depth interviews with 20 parents of children in elementary school, we found that parental involvement takes many forms, including volunteering in the classroom, helping with homework, and communicating with teachers. We also found that parental involvement is influenced by a range of factors, including parent and child characteristics, school culture, and socio-economic status. Our findings suggest that schools and educators should prioritize building strong partnerships with parents to support children’s academic success.

Title : “The Impact of Exercise on Cognitive Function in Older Adults: A Systematic Review and Meta-Analysis”

Abstract : This paper presents a systematic review and meta-analysis of the existing literature on the impact of exercise on cognitive function in older adults. Through the analysis of 25 randomized controlled trials, we found that exercise is associated with significant improvements in cognitive function, particularly in the domains of executive function and attention. Our findings highlight the potential of exercise as a non-pharmacological intervention to support cognitive health in older adults.

When to Write Research Paper Abstract

The abstract of a research paper should typically be written after you have completed the main body of the paper. This is because the abstract is intended to provide a brief summary of the key points and findings of the research, and you can’t do that until you have completed the research and written about it in detail.

Once you have completed your research paper, you can begin writing your abstract. It is important to remember that the abstract should be a concise summary of your research paper, and should be written in a way that is easy to understand for readers who may not have expertise in your specific area of research.

Purpose of Research Paper Abstract

The purpose of a research paper abstract is to provide a concise summary of the key points and findings of a research paper. It is typically a brief paragraph or two that appears at the beginning of the paper, before the introduction, and is intended to give readers a quick overview of the paper’s content.

The abstract should include a brief statement of the research problem, the methods used to investigate the problem, the key results and findings, and the main conclusions and implications of the research. It should be written in a clear and concise manner, avoiding jargon and technical language, and should be understandable to a broad audience.

The abstract serves as a way to quickly and easily communicate the main points of a research paper to potential readers, such as academics, researchers, and students, who may be looking for information on a particular topic. It can also help researchers determine whether a paper is relevant to their own research interests and whether they should read the full paper.

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An abstract summarizes, usually in one paragraph of 300 words or less, the major aspects of the entire paper in a prescribed sequence that includes: 1) the overall purpose of the study and the research problem(s) you investigated; 2) the basic design of the study; 3) major findings or trends found as a result of your analysis; and, 4) a brief summary of your interpretations and conclusions.

Writing an Abstract. The Writing Center. Clarion University, 2009; Writing an Abstract for Your Research Paper. The Writing Center, University of Wisconsin, Madison; Koltay, Tibor. Abstracts and Abstracting: A Genre and Set of Skills for the Twenty-first Century . Oxford, UK: Chandos Publishing, 2010;

Importance of a Good Abstract

Sometimes your professor will ask you to include an abstract, or general summary of your work, with your research paper. The abstract allows you to elaborate upon each major aspect of the paper and helps readers decide whether they want to read the rest of the paper. Therefore, enough key information [e.g., summary results, observations, trends, etc.] must be included to make the abstract useful to someone who may want to examine your work.

How do you know when you have enough information in your abstract? A simple rule-of-thumb is to imagine that you are another researcher doing a similar study. Then ask yourself: if your abstract was the only part of the paper you could access, would you be happy with the amount of information presented there? Does it tell the whole story about your study? If the answer is "no" then the abstract likely needs to be revised.

Farkas, David K. “A Scheme for Understanding and Writing Summaries.” Technical Communication 67 (August 2020): 45-60;  How to Write a Research Abstract. Office of Undergraduate Research. University of Kentucky; Staiger, David L. “What Today’s Students Need to Know about Writing Abstracts.” International Journal of Business Communication January 3 (1966): 29-33; Swales, John M. and Christine B. Feak. Abstracts and the Writing of Abstracts . Ann Arbor, MI: University of Michigan Press, 2009.

Structure and Writing Style

I.  Types of Abstracts

To begin, you need to determine which type of abstract you should include with your paper. There are four general types.

Critical Abstract A critical abstract provides, in addition to describing main findings and information, a judgment or comment about the study’s validity, reliability, or completeness. The researcher evaluates the paper and often compares it with other works on the same subject. Critical abstracts are generally 400-500 words in length due to the additional interpretive commentary. These types of abstracts are used infrequently.

Descriptive Abstract A descriptive abstract indicates the type of information found in the work. It makes no judgments about the work, nor does it provide results or conclusions of the research. It does incorporate key words found in the text and may include the purpose, methods, and scope of the research. Essentially, the descriptive abstract only describes the work being summarized. Some researchers consider it an outline of the work, rather than a summary. Descriptive abstracts are usually very short, 100 words or less. Informative Abstract The majority of abstracts are informative. While they still do not critique or evaluate a work, they do more than describe it. A good informative abstract acts as a surrogate for the work itself. That is, the researcher presents and explains all the main arguments and the important results and evidence in the paper. An informative abstract includes the information that can be found in a descriptive abstract [purpose, methods, scope] but it also includes the results and conclusions of the research and the recommendations of the author. The length varies according to discipline, but an informative abstract is usually no more than 300 words in length.

Highlight Abstract A highlight abstract is specifically written to attract the reader’s attention to the study. No pretense is made of there being either a balanced or complete picture of the paper and, in fact, incomplete and leading remarks may be used to spark the reader’s interest. In that a highlight abstract cannot stand independent of its associated article, it is not a true abstract and, therefore, rarely used in academic writing.

II.  Writing Style

Use the active voice when possible , but note that much of your abstract may require passive sentence constructions. Regardless, write your abstract using concise, but complete, sentences. Get to the point quickly and always use the past tense because you are reporting on a study that has been completed.

Abstracts should be formatted as a single paragraph in a block format and with no paragraph indentations. In most cases, the abstract page immediately follows the title page. Do not number the page. Rules set forth in writing manual vary but, in general, you should center the word "Abstract" at the top of the page with double spacing between the heading and the abstract. The final sentences of an abstract concisely summarize your study’s conclusions, implications, or applications to practice and, if appropriate, can be followed by a statement about the need for additional research revealed from the findings.

Composing Your Abstract

Although it is the first section of your paper, the abstract should be written last since it will summarize the contents of your entire paper. A good strategy to begin composing your abstract is to take whole sentences or key phrases from each section of the paper and put them in a sequence that summarizes the contents. Then revise or add phrases or words to make the narrative flow clearly and smoothly. A useful strategy is to avoid using conjunctions [ e.g. and, but, if] that connect long clauses or sentences and, instead, write short, concise sentences . Note that statistical findings should be reported parenthetically [i.e., written in parentheses].

Before handing in your final paper, check to make sure that the information in the abstract completely agrees with what you have written in the paper. Think of the abstract as a sequential set of complete sentences describing the most crucial information using the fewest necessary words. The abstract SHOULD NOT contain:

• A catchy introductory phrase, provocative quote, or other device to grab the reader's attention,
• Lengthy background or contextual information,
• Redundant phrases, unnecessary adverbs and adjectives, and repetitive information;
• Acronyms or abbreviations,
• References to other literature [say something like, "current research shows that..." or "studies have indicated..."],
• Using ellipticals [i.e., ending with "..."] or incomplete sentences,
• Jargon or terms that may be confusing to the reader,
• Citations to other works, and
• Any sort of image, illustration, figure, or table, or references to them.

Abstract. Writing Center. University of Kansas; Abstract. The Structure, Format, Content, and Style of a Journal-Style Scientific Paper. Department of Biology. Bates College; Abstracts. The Writing Center. University of North Carolina; Borko, Harold and Seymour Chatman. "Criteria for Acceptable Abstracts: A Survey of Abstracters' Instructions." American Documentation 14 (April 1963): 149-160; Abstracts. The Writer’s Handbook. Writing Center. University of Wisconsin, Madison; Hartley, James and Lucy Betts. "Common Weaknesses in Traditional Abstracts in the Social Sciences." Journal of the American Society for Information Science and Technology 60 (October 2009): 2010-2018; Koltay, Tibor. Abstracts and Abstracting: A Genre and Set of Skills for the Twenty-first Century. Oxford, UK: Chandos Publishing, 2010; Procter, Margaret. The Abstract. University College Writing Centre. University of Toronto; Riordan, Laura. “Mastering the Art of Abstracts.” The Journal of the American Osteopathic Association 115 (January 2015 ): 41-47; Writing Report Abstracts. The Writing Lab and The OWL. Purdue University; Writing Abstracts. Writing Tutorial Services, Center for Innovative Teaching and Learning. Indiana University; Koltay, Tibor. Abstracts and Abstracting: A Genre and Set of Skills for the Twenty-First Century . Oxford, UK: 2010; Writing an Abstract for Your Research Paper. The Writing Center, University of Wisconsin, Madison.

Writing Tip

Never Cite Just the Abstract!

Citing to just a journal article's abstract does not confirm for the reader that you have conducted a thorough or reliable review of the literature. If the full-text is not available, go to the USC Libraries main page and enter the title of the article [NOT the title of the journal]. If the Libraries have a subscription to the journal, the article should appear with a link to the full-text or to the journal publisher page where you can get the article. If the article does not appear, try searching Google Scholar using the link on the USC Libraries main page [scroll down under the heading Quick Links]. If you still can't find the article after doing this, contact a librarian or you can request it from our free i nterlibrary loan and document delivery service .

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How to Write an Abstract (With Examples)

By Sarah Oakley

Table of Contents

What is an abstract in a paper, how long should an abstract be, 5 steps for writing an abstract, examples of an abstract, how prowritingaid can help you write an abstract.

If you are writing a scientific research paper or a book proposal, you need to know how to write an abstract, which summarizes the contents of the paper or book.

When researchers are looking for peer-reviewed papers to use in their studies, the first place they will check is the abstract to see if it applies to their work. Therefore, your abstract is one of the most important parts of your entire paper.

In this article, we’ll explain what an abstract is, what it should include, and how to write one.

An abstract is a concise summary of the details within a report. Some abstracts give more details than others, but the main things you’ll be talking about are why you conducted the research, what you did, and what the results show.

When a reader is deciding whether to read your paper completely, they will first look at the abstract. You need to be concise in your abstract and give the reader the most important information so they can determine if they want to read the whole paper.

Remember that an abstract is the last thing you’ll want to write for the research paper because it directly references parts of the report. If you haven’t written the report, you won’t know what to include in your abstract.

If you are writing a paper for a journal or an assignment, the publication or academic institution might have specific formatting rules for how long your abstract should be. However, if they don’t, most abstracts are between 150 and 300 words long.

A short word count means your writing has to be precise and without filler words or phrases. Once you’ve written a first draft, you can always use an editing tool, such as ProWritingAid, to identify areas where you can reduce words and increase readability.

If your abstract is over the word limit, and you’ve edited it but still can’t figure out how to reduce it further, your abstract might include some things that aren’t needed. Here’s a list of three elements you can remove from your abstract:

Discussion : You don’t need to go into detail about the findings of your research because your reader will find your discussion within the paper.

Definition of terms : Your readers are interested the field you are writing about, so they are likely to understand the terms you are using. If not, they can always look them up. Your readers do not expect you to give a definition of terms in your abstract.

References and citations : You can mention there have been studies that support or have inspired your research, but you do not need to give details as the reader will find them in your bibliography.

Good writing = better grades

ProWritingAid will help you improve the style, strength, and clarity of all your assignments.

If you’ve never written an abstract before, and you’re wondering how to write an abstract, we’ve got some steps for you to follow. It’s best to start with planning your abstract, so we’ve outlined the details you need to include in your plan before you write.

Remember to consider your audience when you’re planning and writing your abstract. They are likely to skim read your abstract, so you want to be sure your abstract delivers all the information they’re expecting to see at key points.

1. What Should an Abstract Include?

Abstracts have a lot of information to cover in a short number of words, so it’s important to know what to include. There are three elements that need to be present in your abstract:

Your context is the background for where your research sits within your field of study. You should briefly mention any previous scientific papers or experiments that have led to your hypothesis and how research develops in those studies.

Your hypothesis is your prediction of what your study will show. As you are writing your abstract after you have conducted your research, you should still include your hypothesis in your abstract because it shows the motivation for your paper.

Throughout your abstract, you also need to include keywords and phrases that will help researchers to find your article in the databases they’re searching. Make sure the keywords are specific to your field of study and the subject you’re reporting on, otherwise your article might not reach the relevant audience.

2. Can You Use First Person in an Abstract?

You might think that first person is too informal for a research paper, but it’s not. Historically, writers of academic reports avoided writing in first person to uphold the formality standards of the time. However, first person is more accepted in research papers in modern times.

If you’re still unsure whether to write in first person for your abstract, refer to any style guide rules imposed by the journal you’re writing for or your teachers if you are writing an assignment.

3. Abstract Structure

Some scientific journals have strict rules on how to structure an abstract, so it’s best to check those first. If you don’t have any style rules to follow, try using the IMRaD structure, which stands for Introduction, Methodology, Results, and Discussion.

Following the IMRaD structure, start with an introduction. The amount of background information you should include depends on your specific research area. Adding a broad overview gives you less room to include other details. Remember to include your hypothesis in this section.

The next part of your abstract should cover your methodology. Try to include the following details if they apply to your study:

What type of research was conducted?

How were the test subjects sampled?

What were the sample sizes?

What was done to each group?

How long was the experiment?

How was data recorded and interpreted?

Following the methodology, include a sentence or two about the results, which is where your reader will determine if your research supports or contradicts their own investigations.

The results are also where most people will want to find out what your outcomes were, even if they are just mildly interested in your research area. You should be specific about all the details but as concise as possible.

The last few sentences are your conclusion. It needs to explain how your findings affect the context and whether your hypothesis was correct. Include the primary take-home message, additional findings of importance, and perspective. Also explain whether there is scope for further research into the subject of your report.

Your conclusion should be honest and give the reader the ultimate message that your research shows. Readers trust the conclusion, so make sure you’re not fabricating the results of your research. Some readers won’t read your entire paper, but this section will tell them if it’s worth them referencing it in their own study.

4. How to Start an Abstract

The first line of your abstract should give your reader the context of your report by providing background information. You can use this sentence to imply the motivation for your research.

You don’t need to use a hook phrase or device in your first sentence to grab the reader’s attention. Your reader will look to establish relevance quickly, so readability and clarity are more important than trying to persuade the reader to read on.

5. How to Format an Abstract

Most abstracts use the same formatting rules, which help the reader identify the abstract so they know where to look for it.

Here’s a list of formatting guidelines for writing an abstract:

Stick to one paragraph

Use block formatting with no indentation at the beginning

Put your abstract straight after the title and acknowledgements pages

Use present or past tense, not future tense

There are two primary types of abstract you could write for your paper—descriptive and informative.

An informative abstract is the most common, and they follow the structure mentioned previously. They are longer than descriptive abstracts because they cover more details.

Descriptive abstracts differ from informative abstracts, as they don’t include as much discussion or detail. The word count for a descriptive abstract is between 50 and 150 words.

Here is an example of an informative abstract:

A growing trend exists for authors to employ a more informal writing style that uses “we” in academic writing to acknowledge one’s stance and engagement. However, few studies have compared the ways in which the first-person pronoun “we” is used in the abstracts and conclusions of empirical papers. To address this lacuna in the literature, this study conducted a systematic corpus analysis of the use of “we” in the abstracts and conclusions of 400 articles collected from eight leading electrical and electronic (EE) engineering journals. The abstracts and conclusions were extracted to form two subcorpora, and an integrated framework was applied to analyze and seek to explain how we-clusters and we-collocations were employed. Results revealed whether authors’ use of first-person pronouns partially depends on a journal policy. The trend of using “we” showed that a yearly increase occurred in the frequency of “we” in EE journal papers, as well as the existence of three “we-use” types in the article conclusions and abstracts: exclusive, inclusive, and ambiguous. Other possible “we-use” alternatives such as “I” and other personal pronouns were used very rarely—if at all—in either section. These findings also suggest that the present tense was used more in article abstracts, but the present perfect tense was the most preferred tense in article conclusions. Both research and pedagogical implications are proffered and critically discussed.

Wang, S., Tseng, W.-T., & Johanson, R. (2021). To We or Not to We: Corpus-Based Research on First-Person Pronoun Use in Abstracts and Conclusions. SAGE Open, 11(2).

Here is an example of a descriptive abstract:

From the 1850s to the present, considerable criminological attention has focused on the development of theoretically-significant systems for classifying crime. This article reviews and attempts to evaluate a number of these efforts, and we conclude that further work on this basic task is needed. The latter part of the article explicates a conceptual foundation for a crime pattern classification system, and offers a preliminary taxonomy of crime.

Farr, K. A., & Gibbons, D. C. (1990). Observations on the Development of Crime Categories. International Journal of Offender Therapy and Comparative Criminology, 34(3), 223–237.

If you want to ensure your abstract is grammatically correct and easy to read, you can use ProWritingAid to edit it. The software integrates with Microsoft Word, Google Docs, and most web browsers, so you can make the most of it wherever you’re writing your paper.

Before you edit with ProWritingAid, make sure the suggestions you are seeing are relevant for your document by changing the document type to “Abstract” within the Academic writing style section.

You can use the Readability report to check your abstract for places to improve the clarity of your writing. Some suggestions might show you where to remove words, which is great if you’re over your word count.

We hope the five steps and examples we’ve provided help you write a great abstract for your research paper.

Sarah Oakley

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How to write an abstract

What is an abstract?

General format of an abstract, the content of an abstract, abstract example, abstract style guides, frequently asked questions about writing an abstract, related articles.

An abstract is a summary of the main contents of a paper.

The abstract is the first glimpse that readers get of the content of a research paper. It can influence the popularity of a paper, as a well-written one will attract readers, and a poorly-written one will drive them away.

➡️ Different types of papers may require distinct abstract styles. Visit our guide on the different types of research papers to learn more.

Tip: Always wait until you’ve written your entire paper before you write the abstract.

Before you actually start writing an abstract, make sure to follow these steps:

• Read other papers : find papers with similar topics, or similar methodologies, simply to have an idea of how others have written their abstracts. Notice which points they decided to include, and how in depth they described them.
• Double check the journal requirements : always make sure to review the journal guidelines to format your paper accordingly. Usually, they also specify abstract's formats.
• Write the abstract after you finish writing the paper : you can only write an abstract once you finish writing the whole paper. This way you can include all important aspects, such as scope, methodology, and conclusion.

➡️ Read more about  what is a research methodology?

The general format of an abstract includes the following features:

• Between 150-300 words .
• An independent page , after the title page and before the table of contents.
• Concise summary including the aim of the research, methodology , and conclusion .
• Keywords describing the content.

As mentioned before, an abstract is a text that summarizes the main points of a research. Here is a break down of each element that should be included in an abstract:

• Purpose : every abstract should start by describing the main purpose or aim of the research.
• Methods : as a second point, the methodology carried out should be explained.
• Results : then, a concise summary of the results should be included.
• Conclusion : finally, a short outline of the general outcome of the research should be given.
• Keywords : along with the abstract, specific words and phrases related to the topics discussed in the research should be added. These words are usually around five, but the number can vary depending on the journal's guidelines.

This abstract, taken from ScienceDirect , illustrates the ideal structure of an abstract. It has 155 words, it's concise, and it clearly shows the division of elements necessary to write a successful abstract.

This paper explores the implicit assumption in the growing body of literature that social media usage is fundamentally different in business-to-business (B2B) companies than in the extant business-to-consumer (B2C) literature. Sashi's (2012) customer engagement cycle is utilized to compare organizational practices in relation to social media marketing in B2B, B2C, Mixed B2B/B2C and B2B2C business models. Utilizing 449 responses to an exploratory panel based survey instrument, we clearly identify differences in social media usage and its perceived importance as a communications channel. In particular we identify distinct differences in the relationship between social media importance and the perceived effectiveness of social media marketing across business models. Our results indicate that B2B social media usage is distinct from B2C, Mixed and B2B2C business model approaches. Specifically B2B organizational members perceive social media to have a lower overall effectiveness as a channel and identify it as less important for relationship oriented usage than other business models.

The exact format of an abstract depends on the citation style you implement. Whether it’s a well-known style (like APA, IEEE, etc.) or a journal's style, each format has its own guidelines, so make sure you know which style you are using before writing your abstract.

APA is one of the most commonly used styles to format an abstract. Therefore, we created a guide with exact instructions on how to write an abstract in APA style, and a template to download:

📕 APA abstract page: format and template

Additionally, you will find below an IEEE and ASA abstract guide by Purdue Online Writing Lab :

📗 IEEE General Format - Abstract

📘 ASA Manuscript Formatting - Abstract

No. You should always write an abstract once you finish writing the whole paper. This way you can include all important aspects of the paper, such as scope, methodology, and conclusion.

The length of an abstract depends on the formatting style of the paper. For example, APA style calls for 150 to 250 words. Generally, you need between 150-300 words.

No. An abstract has an independent section after the title page and before the table of contents, and should not be included in the table of contents.

Take a look at APA abstract page: format and template for exact details on how to format an abstract in APA style.

You can access any paper through Google Scholar or any other search engine; pick a paper and read the abstract. Abstracts are always freely available to read.

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Getting a paper out there is great. Getting the words on the paper can be painful. Here is an easy manual for how to write an abstract that requires minimal effort.

The purpose of an abstract is to spark the reader’s interest in the story and motivate them to continue reading the whole paper. It might be obvious, but it is worth pointing out that people only cite your work if they have read it. A compelling writing style is a first step in that direction because a well-written paper is more likely to have a large readership.

Consider an abstract a 5-part structure consisting of 1) introduction, 2) problem/objective, 3) “Here we show”, 4) main results & conclusions, and 5) implications.

1) Introduction (2 sentences):

    --> Sentence 1: Basic introduction to the field; accessible to scientists of any  discipline.

    --> Sentence 2: Background of the specific research question; comprehensible to scientists in the same or closely related fields of research.

2) Problem/objective (1 sentence):

    --> Explanation what is missing/unknown/problematic, i.e. why the current study happened. Typically, this sentence starts with “However”.

3) “Here we show” (1 sentence):

    --> The main result/key finding summarised in one sentence, which starts with “Here we show”.

4) Main results and conclusions (~ 3 – 5 sentences)

    --> Summary of the most important findings of the study that are the foundation of the main conclusions. A few key bits of data are welcome but adding too many numbers is off-putting to the reader. Keep it focussed.

    --> Unless the method is new and/or a main part of the paper, there’s no need to include any details in the abstract. If you mentioned, it should be included in a sentence along the lines of “Using xyz, we show that (…)”.

5) Implications (1 – 2 sentences)

    --> Some explanation on how your findings advance the field. Where does your work lead and what are the immediate implications? The word “immediate” is key here because being too creative or hyping the work are pitfalls that should be avoided. Rather, keep it realistic and explain which opportunities your work offer and/or what it leads to.

If you hit the five marks above in exactly this order, your abstract is likely to tell a compelling story. Of course, there are also some journal-specific formatting requirements for your abstract. For instance, for Nature Communications those are: 150 words max., no references or unnecessary abbreviations/acronyms, and the results should be presented in the present tense.

The target audience

One last piece of advice: When writing the abstract and, in fact, your whole paper, consider your ultimate audience, which are active scientists not editors. Getting published is only the first step. Eventually, your paper is supposed to attract as many readers as possible so it gets the exposure and attention it deserves.

Further writing advice and courses

Of course, there is much more to writing a compelling paper, and I might write further posts on this matter. For those who would like to boost their skills in scientific writing and better understand how to navigate the publishing system, Springer Nature offers Nature Masterclasses which include face-to-face workshops , webinars , and online training courses (free sample here and free online course “Focus on Peer Review” here ).

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• How to Write an Abstract | Steps & Examples

How to Write an Abstract | Steps & Examples

Published on 1 March 2019 by Shona McCombes . Revised on 10 October 2022 by Eoghan Ryan.

An abstract is a short summary of a longer work (such as a dissertation or research paper ). The abstract concisely reports the aims and outcomes of your research, so that readers know exactly what your paper is about.

Although the structure may vary slightly depending on your discipline, your abstract should describe the purpose of your work, the methods you’ve used, and the conclusions you’ve drawn.

One common way to structure your abstract is to use the IMRaD structure. This stands for:

• Introduction

Abstracts are usually around 100–300 words, but there’s often a strict word limit, so make sure to check the relevant requirements.

In a dissertation or thesis , include the abstract on a separate page, after the title page and acknowledgements but before the table of contents .

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Table of contents

Abstract example, when to write an abstract, step 1: introduction, step 2: methods, step 3: results, step 4: discussion, tips for writing an abstract, frequently asked questions about abstracts.

Hover over the different parts of the abstract to see how it is constructed.

This paper examines the role of silent movies as a mode of shared experience in the UK during the early twentieth century. At this time, high immigration rates resulted in a significant percentage of non-English-speaking citizens. These immigrants faced numerous economic and social obstacles, including exclusion from public entertainment and modes of discourse (newspapers, theater, radio).

Incorporating evidence from reviews, personal correspondence, and diaries, this study demonstrates that silent films were an affordable and inclusive source of entertainment. It argues for the accessible economic and representational nature of early cinema. These concerns are particularly evident in the low price of admission and in the democratic nature of the actors’ exaggerated gestures, which allowed the plots and action to be easily grasped by a diverse audience despite language barriers.

Keywords: silent movies, immigration, public discourse, entertainment, early cinema, language barriers.

Prevent plagiarism, run a free check.

You will almost always have to include an abstract when:

• Completing a thesis or dissertation
• Submitting a research paper to an academic journal
• Writing a book proposal
• Applying for research grants

It’s easiest to write your abstract last, because it’s a summary of the work you’ve already done. Your abstract should:

• Be a self-contained text, not an excerpt from your paper
• Be fully understandable on its own
• Reflect the structure of your larger work

Start by clearly defining the purpose of your research. What practical or theoretical problem does the research respond to, or what research question did you aim to answer?

You can include some brief context on the social or academic relevance of your topic, but don’t go into detailed background information. If your abstract uses specialised terms that would be unfamiliar to the average academic reader or that have various different meanings, give a concise definition.

After identifying the problem, state the objective of your research. Use verbs like “investigate,” “test,” “analyse,” or “evaluate” to describe exactly what you set out to do.

This part of the abstract can be written in the present or past simple tense  but should never refer to the future, as the research is already complete.

• This study will investigate the relationship between coffee consumption and productivity.
• This study investigates the relationship between coffee consumption and productivity.

Next, indicate the research methods that you used to answer your question. This part should be a straightforward description of what you did in one or two sentences. It is usually written in the past simple tense, as it refers to completed actions.

• Structured interviews will be conducted with 25 participants.
• Structured interviews were conducted with 25 participants.

Don’t evaluate validity or obstacles here — the goal is not to give an account of the methodology’s strengths and weaknesses, but to give the reader a quick insight into the overall approach and procedures you used.

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Next, summarise the main research results . This part of the abstract can be in the present or past simple tense.

• Our analysis has shown a strong correlation between coffee consumption and productivity.
• Our analysis shows a strong correlation between coffee consumption and productivity.
• Our analysis showed a strong correlation between coffee consumption and productivity.

Depending on how long and complex your research is, you may not be able to include all results here. Try to highlight only the most important findings that will allow the reader to understand your conclusions.

Finally, you should discuss the main conclusions of your research : what is your answer to the problem or question? The reader should finish with a clear understanding of the central point that your research has proved or argued. Conclusions are usually written in the present simple tense.

• We concluded that coffee consumption increases productivity.
• We conclude that coffee consumption increases productivity.

If there are important limitations to your research (for example, related to your sample size or methods), you should mention them briefly in the abstract. This allows the reader to accurately assess the credibility and generalisability of your research.

If your aim was to solve a practical problem, your discussion might include recommendations for implementation. If relevant, you can briefly make suggestions for further research.

If your paper will be published, you might have to add a list of keywords at the end of the abstract. These keywords should reference the most important elements of the research to help potential readers find your paper during their own literature searches.

Be aware that some publication manuals, such as APA Style , have specific formatting requirements for these keywords.

It can be a real challenge to condense your whole work into just a couple of hundred words, but the abstract will be the first (and sometimes only) part that people read, so it’s important to get it right. These strategies can help you get started.

Read other abstracts

The best way to learn the conventions of writing an abstract in your discipline is to read other people’s. You probably already read lots of journal article abstracts while conducting your literature review —try using them as a framework for structure and style.

You can also find lots of dissertation abstract examples in thesis and dissertation databases .

Reverse outline

Not all abstracts will contain precisely the same elements. For longer works, you can write your abstract through a process of reverse outlining.

For each chapter or section, list keywords and draft one to two sentences that summarise the central point or argument. This will give you a framework of your abstract’s structure. Next, revise the sentences to make connections and show how the argument develops.

Write clearly and concisely

A good abstract is short but impactful, so make sure every word counts. Each sentence should clearly communicate one main point.

To keep your abstract or summary short and clear:

• Avoid passive sentences: Passive constructions are often unnecessarily long. You can easily make them shorter and clearer by using the active voice.
• Avoid long sentences: Substitute longer expressions for concise expressions or single words (e.g., “In order to” for “To”).
• Avoid obscure jargon: The abstract should be understandable to readers who are not familiar with your topic.
• Avoid repetition and filler words: Replace nouns with pronouns when possible and eliminate unnecessary words.
• Avoid detailed descriptions: An abstract is not expected to provide detailed definitions, background information, or discussions of other scholars’ work. Instead, include this information in the body of your thesis or paper.

If you’re struggling to edit down to the required length, you can get help from expert editors with Scribbr’s professional proofreading services .

Check your formatting

If you are writing a thesis or dissertation or submitting to a journal, there are often specific formatting requirements for the abstract—make sure to check the guidelines and format your work correctly. For APA research papers you can follow the APA abstract format .

Checklist: Abstract

The word count is within the required length, or a maximum of one page.

The abstract appears after the title page and acknowledgements and before the table of contents .

I have clearly stated my research problem and objectives.

I have briefly described my methodology .

I have summarized the most important results .

I have stated my main conclusions .

I have mentioned any important limitations and recommendations.

The abstract can be understood by someone without prior knowledge of the topic.

You've written a great abstract! Use the other checklists to continue improving your thesis or dissertation.

An abstract is a concise summary of an academic text (such as a journal article or dissertation ). It serves two main purposes:

• To help potential readers determine the relevance of your paper for their own research.
• To communicate your key findings to those who don’t have time to read the whole paper.

Abstracts are often indexed along with keywords on academic databases, so they make your work more easily findable. Since the abstract is the first thing any reader sees, it’s important that it clearly and accurately summarises the contents of your paper.

An abstract for a thesis or dissertation is usually around 150–300 words. There’s often a strict word limit, so make sure to check your university’s requirements.

The abstract is the very last thing you write. You should only write it after your research is complete, so that you can accurately summarize the entirety of your thesis or paper.

Avoid citing sources in your abstract . There are two reasons for this:

• The abstract should focus on your original research, not on the work of others.
• The abstract should be self-contained and fully understandable without reference to other sources.

There are some circumstances where you might need to mention other sources in an abstract: for example, if your research responds directly to another study or focuses on the work of a single theorist. In general, though, don’t include citations unless absolutely necessary.

The abstract appears on its own page, after the title page and acknowledgements but before the table of contents .

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the ‘Cite this Scribbr article’ button to automatically add the citation to our free Reference Generator.

McCombes, S. (2022, October 10). How to Write an Abstract | Steps & Examples. Scribbr. Retrieved 3 September 2024, from https://www.scribbr.co.uk/thesis-dissertation/abstract/

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Abstract Writing: A Step-by-Step Guide With Tips & Examples

Table of Contents

Introduction

Abstracts of research papers have always played an essential role in describing your research concisely and clearly to researchers and editors of journals, enticing them to continue reading. However, with the widespread availability of scientific databases, the need to write a convincing abstract is more crucial now than during the time of paper-bound manuscripts.

Abstracts serve to "sell" your research and can be compared with your "executive outline" of a resume or, rather, a formal summary of the critical aspects of your work. Also, it can be the "gist" of your study. Since most educational research is done online, it's a sign that you have a shorter time for impressing your readers, and have more competition from other abstracts that are available to be read.

The APCI (Academic Publishing and Conferences International) articulates 12 issues or points considered during the final approval process for conferences & journals and emphasises the importance of writing an abstract that checks all these boxes (12 points). Since it's the only opportunity you have to captivate your readers, you must invest time and effort in creating an abstract that accurately reflects the critical points of your research.

With that in mind, let’s head over to understand and discover the core concept and guidelines to create a substantial abstract. Also, learn how to organise the ideas or plots into an effective abstract that will be awe-inspiring to the readers you want to reach.

What is Abstract? Definition and Overview

The word "Abstract' is derived from Latin abstractus meaning "drawn off." This etymological meaning also applies to art movements as well as music, like abstract expressionism. In this context, it refers to the revealing of the artist's intention.

Based on this, you can determine the meaning of an abstract: A condensed research summary. It must be self-contained and independent of the body of the research. However, it should outline the subject, the strategies used to study the problem, and the methods implemented to attain the outcomes. The specific elements of the study differ based on the area of study; however, together, it must be a succinct summary of the entire research paper.

Abstracts are typically written at the end of the paper, even though it serves as a prologue. In general, the abstract must be in a position to:

• Describe the paper.
• Identify the problem or the issue at hand.
• Explain to the reader the research process, the results you came up with, and what conclusion you've reached using these results.
• Include keywords to guide your strategy and the content.

Furthermore, the abstract you submit should not reflect upon any of  the following elements:

• Examine, analyse or defend the paper or your opinion.
• What you want to study, achieve or discover.
• Be redundant or irrelevant.

After reading an abstract, your audience should understand the reason - what the research was about in the first place, what the study has revealed and how it can be utilised or can be used to benefit others. You can understand the importance of abstract by knowing the fact that the abstract is the most frequently read portion of any research paper. In simpler terms, it should contain all the main points of the research paper.

What is the Purpose of an Abstract?

Abstracts are typically an essential requirement for research papers; however, it's not an obligation to preserve traditional reasons without any purpose. Abstracts allow readers to scan the text to determine whether it is relevant to their research or studies. The abstract allows other researchers to decide if your research paper can provide them with some additional information. A good abstract paves the interest of the audience to pore through your entire paper to find the content or context they're searching for.

Abstract writing is essential for indexing, as well. The Digital Repository of academic papers makes use of abstracts to index the entire content of academic research papers. Like meta descriptions in the regular Google outcomes, abstracts must include keywords that help researchers locate what they seek.

Types of Abstract

Informative and Descriptive are two kinds of abstracts often used in scientific writing.

A descriptive abstract gives readers an outline of the author's main points in their study. The reader can determine if they want to stick to the research work, based on their interest in the topic. An abstract that is descriptive is similar to the contents table of books, however, the format of an abstract depicts complete sentences encapsulated in one paragraph. It is unfortunate that the abstract can't be used as a substitute for reading a piece of writing because it's just an overview, which omits readers from getting an entire view. Also, it cannot be a way to fill in the gaps the reader may have after reading this kind of abstract since it does not contain crucial information needed to evaluate the article.

To conclude, a descriptive abstract is:

• A simple summary of the task, just summarises the work, but some researchers think it is much more of an outline
• Typically, the length is approximately 100 words. It is too short when compared to an informative abstract.
• A brief explanation but doesn't provide the reader with the complete information they need;
• An overview that omits conclusions and results

An informative abstract is a comprehensive outline of the research. There are times when people rely on the abstract as an information source. And the reason is why it is crucial to provide entire data of particular research. A well-written, informative abstract could be a good substitute for the remainder of the paper on its own.

A well-written abstract typically follows a particular style. The author begins by providing the identifying information, backed by citations and other identifiers of the papers. Then, the major elements are summarised to make the reader aware of the study. It is followed by the methodology and all-important findings from the study. The conclusion then presents study results and ends the abstract with a comprehensive summary.

In a nutshell, an informative abstract:

• Has a length that can vary, based on the subject, but is not longer than 300 words.
• Contains all the content-like methods and intentions
• Offers evidence and possible recommendations.

Informative Abstracts are more frequent than descriptive abstracts because of their extensive content and linkage to the topic specifically. You should select different types of abstracts to papers based on their length: informative abstracts for extended and more complex abstracts and descriptive ones for simpler and shorter research papers.

What are the Characteristics of a Good Abstract?

• A good abstract clearly defines the goals and purposes of the study.
• It should clearly describe the research methodology with a primary focus on data gathering, processing, and subsequent analysis.
• A good abstract should provide specific research findings.
• It presents the principal conclusions of the systematic study.
• It should be concise, clear, and relevant to the field of study.
• A well-designed abstract should be unifying and coherent.
• It is easy to grasp and free of technical jargon.
• It is written impartially and objectively.

You can have a thorough understanding of abstracts using SciSpace ChatPDF which makes your abstract analysis part easier.

What are the various sections of an ideal Abstract?

By now, you must have gained some concrete idea of the essential elements that your abstract needs to convey . Accordingly, the information is broken down into six key sections of the abstract, which include:

An Introduction or Background

Research methodology, objectives and goals, limitations.

Let's go over them in detail.

The introduction, also known as background, is the most concise part of your abstract. Ideally, it comprises a couple of sentences. Some researchers only write one sentence to introduce their abstract. The idea behind this is to guide readers through the key factors that led to your study.

It's understandable that this information might seem difficult to explain in a couple of sentences. For example, think about the following two questions like the background of your study:

• What is currently available about the subject with respect to the paper being discussed?
• What isn't understood about this issue? (This is the subject of your research)

While writing the abstract’s introduction, make sure that it is not lengthy. Because if it crosses the word limit, it may eat up the words meant to be used for providing other key information.

Research methodology is where you describe the theories and techniques you used in your research. It is recommended that you describe what you have done and the method you used to get your thorough investigation results. Certainly, it is the second-longest paragraph in the abstract.

In the research methodology section, it is essential to mention the kind of research you conducted; for instance, qualitative research or quantitative research (this will guide your research methodology too) . If you've conducted quantitative research, your abstract should contain information like the sample size, data collection method, sampling techniques, and duration of the study. Likewise, your abstract should reflect observational data, opinions, questionnaires (especially the non-numerical data) if you work on qualitative research.

The research objectives and goals speak about what you intend to accomplish with your research. The majority of research projects focus on the long-term effects of a project, and the goals focus on the immediate, short-term outcomes of the research. It is possible to summarise both in just multiple sentences.

In stating your objectives and goals, you give readers a picture of the scope of the study, its depth and the direction your research ultimately follows. Your readers can evaluate the results of your research against the goals and stated objectives to determine if you have achieved the goal of your research.

In the end, your readers are more attracted by the results you've obtained through your study. Therefore, you must take the time to explain each relevant result and explain how they impact your research. The results section exists as the longest in your abstract, and nothing should diminish its reach or quality.

One of the most important things you should adhere to is to spell out details and figures on the results of your research.

Instead of making a vague assertion such as, "We noticed that response rates varied greatly between respondents with high incomes and those with low incomes", Try these: "The response rate was higher for high-income respondents than those with lower incomes (59 30 percent vs. 30 percent in both cases; P<0.01)."

You're likely to encounter certain obstacles during your research. It could have been during data collection or even during conducting the sample . Whatever the issue, it's essential to inform your readers about them and their effects on the research.

Research limitations offer an opportunity to suggest further and deep research. If, for instance, you were forced to change for convenient sampling and snowball samples because of difficulties in reaching well-suited research participants, then you should mention this reason when you write your research abstract. In addition, a lack of prior studies on the subject could hinder your research.

Your conclusion should include the same number of sentences to wrap the abstract as the introduction. The majority of researchers offer an idea of the consequences of their research in this case.

Your conclusion should include three essential components:

• A significant take-home message.
• Corresponding important findings.
• The Interpretation.

Even though the conclusion of your abstract needs to be brief, it can have an enormous influence on the way that readers view your research. Therefore, make use of this section to reinforce the central message from your research. Be sure that your statements reflect the actual results and the methods you used to conduct your research.

Good Abstract Examples

Abstract example #1.

Children’s consumption behavior in response to food product placements in movies.

The abstract:

"Almost all research into the effects of brand placements on children has focused on the brand's attitudes or behavior intentions. Based on the significant differences between attitudes and behavioral intentions on one hand and actual behavior on the other hand, this study examines the impact of placements by brands on children's eating habits. Children aged 6-14 years old were shown an excerpt from the popular film Alvin and the Chipmunks and were shown places for the item Cheese Balls. Three different versions were developed with no placements, one with moderately frequent placements and the third with the highest frequency of placement. The results revealed that exposure to high-frequency places had a profound effect on snack consumption, however, there was no impact on consumer attitudes towards brands or products. The effects were not dependent on the age of the children. These findings are of major importance to researchers studying consumer behavior as well as nutrition experts as well as policy regulators."

Abstract Example #2

Social comparisons on social media: The impact of Facebook on young women’s body image concerns and mood. The abstract:

"The research conducted in this study investigated the effects of Facebook use on women's moods and body image if the effects are different from an internet-based fashion journal and if the appearance comparison tendencies moderate one or more of these effects. Participants who were female ( N = 112) were randomly allocated to spend 10 minutes exploring their Facebook account or a magazine's website or an appearance neutral control website prior to completing state assessments of body dissatisfaction, mood, and differences in appearance (weight-related and facial hair, face, and skin). Participants also completed a test of the tendency to compare appearances. The participants who used Facebook were reported to be more depressed than those who stayed on the control site. In addition, women who have the tendency to compare appearances reported more facial, hair and skin-related issues following Facebook exposure than when they were exposed to the control site. Due to its popularity it is imperative to conduct more research to understand the effect that Facebook affects the way people view themselves."

Abstract Example #3

The Relationship Between Cell Phone Use and Academic Performance in a Sample of U.S. College Students

"The cellphone is always present on campuses of colleges and is often utilised in situations in which learning takes place. The study examined the connection between the use of cell phones and the actual grades point average (GPA) after adjusting for predictors that are known to be a factor. In the end 536 students in the undergraduate program from 82 self-reported majors of an enormous, public institution were studied. Hierarchical analysis ( R 2 = .449) showed that use of mobile phones is significantly ( p < .001) and negative (b equal to -.164) connected to the actual college GPA, after taking into account factors such as demographics, self-efficacy in self-regulated learning, self-efficacy to improve academic performance, and the actual high school GPA that were all important predictors ( p < .05). Therefore, after adjusting for other known predictors increasing cell phone usage was associated with lower academic performance. While more research is required to determine the mechanisms behind these results, they suggest the need to educate teachers and students to the possible academic risks that are associated with high-frequency mobile phone usage."

Quick tips on writing a good abstract

There exists a common dilemma among early age researchers whether to write the abstract at first or last? However, it's recommended to compose your abstract when you've completed the research since you'll have all the information to give to your readers. You can, however, write a draft at the beginning of your research and add in any gaps later.

If you find abstract writing a herculean task, here are the few tips to help you with it:

1. Always develop a framework to support your abstract

Before writing, ensure you create a clear outline for your abstract. Divide it into sections and draw the primary and supporting elements in each one. You can include keywords and a few sentences that convey the essence of your message.

2. Review Other Abstracts

Abstracts are among the most frequently used research documents, and thousands of them were written in the past. Therefore, prior to writing yours, take a look at some examples from other abstracts. There are plenty of examples of abstracts for dissertations in the dissertation and thesis databases.

3. Avoid Jargon To the Maximum

When you write your abstract, focus on simplicity over formality. You should  write in simple language, and avoid excessive filler words or ambiguous sentences. Keep in mind that your abstract must be readable to those who aren't acquainted with your subject.

4. Focus on Your Research

It's a given fact that the abstract you write should be about your research and the findings you've made. It is not the right time to mention secondary and primary data sources unless it's absolutely required.

Conclusion: How to Structure an Interesting Abstract?

Abstracts are a short outline of your essay. However, it's among the most important, if not the most important. The process of writing an abstract is not straightforward. A few early-age researchers tend to begin by writing it, thinking they are doing it to "tease" the next step (the document itself). However, it is better to treat it as a spoiler.

The simple, concise style of the abstract lends itself to a well-written and well-investigated study. If your research paper doesn't provide definitive results, or the goal of your research is questioned, so will the abstract. Thus, only write your abstract after witnessing your findings and put your findings in the context of a larger scenario.

The process of writing an abstract can be daunting, but with these guidelines, you will succeed. The most efficient method of writing an excellent abstract is to centre the primary points of your abstract, including the research question and goals methods, as well as key results.

Interested in learning more about dedicated research solutions? Go to the SciSpace product page to find out how our suite of products can help you simplify your research workflows so you can focus on advancing science.

The best-in-class solution is equipped with features such as literature search and discovery, profile management, research writing and formatting, and so much more.

But before you go,

You might also like.

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Types of Essays in Academic Writing - Quick Guide (2024)

What this handout is about

This handout provides definitions and examples of the two main types of abstracts: descriptive and informative. It also provides guidelines for constructing an abstract and general tips for you to keep in mind when drafting. Finally, it includes a few examples of abstracts broken down into their component parts.

What is an abstract?

An abstract is a self-contained, short, and powerful statement that describes a larger work. Components vary according to discipline. An abstract of a social science or scientific work may contain the scope, purpose, results, and contents of the work. An abstract of a humanities work may contain the thesis, background, and conclusion of the larger work. An abstract is not a review, nor does it evaluate the work being abstracted. While it contains key words found in the larger work, the abstract is an original document rather than an excerpted passage.

Why write an abstract?

You may write an abstract for various reasons. The two most important are selection and indexing. Abstracts allow readers who may be interested in a longer work to quickly decide whether it is worth their time to read it. Also, many online databases use abstracts to index larger works. Therefore, abstracts should contain keywords and phrases that allow for easy searching.

Say you are beginning a research project on how Brazilian newspapers helped Brazil’s ultra-liberal president Luiz Ignácio da Silva wrest power from the traditional, conservative power base. A good first place to start your research is to search Dissertation Abstracts International for all dissertations that deal with the interaction between newspapers and politics. “Newspapers and politics” returned 569 hits. A more selective search of “newspapers and Brazil” returned 22 hits. That is still a fair number of dissertations. Titles can sometimes help winnow the field, but many titles are not very descriptive. For example, one dissertation is titled “Rhetoric and Riot in Rio de Janeiro.” It is unclear from the title what this dissertation has to do with newspapers in Brazil. One option would be to download or order the entire dissertation on the chance that it might speak specifically to the topic. A better option is to read the abstract. In this case, the abstract reveals the main focus of the dissertation:

This dissertation examines the role of newspaper editors in the political turmoil and strife that characterized late First Empire Rio de Janeiro (1827-1831). Newspaper editors and their journals helped change the political culture of late First Empire Rio de Janeiro by involving the people in the discussion of state. This change in political culture is apparent in Emperor Pedro I’s gradual loss of control over the mechanisms of power. As the newspapers became more numerous and powerful, the Emperor lost his legitimacy in the eyes of the people. To explore the role of the newspapers in the political events of the late First Empire, this dissertation analyzes all available newspapers published in Rio de Janeiro from 1827 to 1831. Newspapers and their editors were leading forces in the effort to remove power from the hands of the ruling elite and place it under the control of the people. In the process, newspapers helped change how politics operated in the constitutional monarchy of Brazil.

From this abstract you now know that although the dissertation has nothing to do with modern Brazilian politics, it does cover the role of newspapers in changing traditional mechanisms of power. After reading the abstract, you can make an informed judgment about whether the dissertation would be worthwhile to read.

Besides selection, the other main purpose of the abstract is for indexing. Most article databases in the online catalog of the library enable you to search abstracts. This allows for quick retrieval by users and limits the extraneous items recalled by a “full-text” search. However, for an abstract to be useful in an online retrieval system, it must incorporate the key terms that a potential researcher would use to search. For example, if you search Dissertation Abstracts International using the keywords “France” “revolution” and “politics,” the search engine would search through all the abstracts in the database that included those three words. Without an abstract, the search engine would be forced to search titles, which, as we have seen, may not be fruitful, or else search the full text. It’s likely that a lot more than 60 dissertations have been written with those three words somewhere in the body of the entire work. By incorporating keywords into the abstract, the author emphasizes the central topics of the work and gives prospective readers enough information to make an informed judgment about the applicability of the work.

When do people write abstracts?

• when submitting articles to journals, especially online journals
• when applying for research grants
• when writing a book proposal
• when completing the Ph.D. dissertation or M.A. thesis
• when writing a proposal for a conference paper
• when writing a proposal for a book chapter

Most often, the author of the entire work (or prospective work) writes the abstract. However, there are professional abstracting services that hire writers to draft abstracts of other people’s work. In a work with multiple authors, the first author usually writes the abstract. Undergraduates are sometimes asked to draft abstracts of books/articles for classmates who have not read the larger work.

Types of abstracts

There are two types of abstracts: descriptive and informative. They have different aims, so as a consequence they have different components and styles. There is also a third type called critical, but it is rarely used. If you want to find out more about writing a critique or a review of a work, see the UNC Writing Center handout on writing a literature review . If you are unsure which type of abstract you should write, ask your instructor (if the abstract is for a class) or read other abstracts in your field or in the journal where you are submitting your article.

Descriptive abstracts

A descriptive abstract indicates the type of information found in the work. It makes no judgments about the work, nor does it provide results or conclusions of the research. It does incorporate key words found in the text and may include the purpose, methods, and scope of the research. Essentially, the descriptive abstract describes the work being abstracted. Some people consider it an outline of the work, rather than a summary. Descriptive abstracts are usually very short—100 words or less.

Informative abstracts

The majority of abstracts are informative. While they still do not critique or evaluate a work, they do more than describe it. A good informative abstract acts as a surrogate for the work itself. That is, the writer presents and explains all the main arguments and the important results and evidence in the complete article/paper/book. An informative abstract includes the information that can be found in a descriptive abstract (purpose, methods, scope) but also includes the results and conclusions of the research and the recommendations of the author. The length varies according to discipline, but an informative abstract is rarely more than 10% of the length of the entire work. In the case of a longer work, it may be much less.

Here are examples of a descriptive and an informative abstract of this handout on abstracts . Descriptive abstract:

The two most common abstract types—descriptive and informative—are described and examples of each are provided.

Informative abstract:

Abstracts present the essential elements of a longer work in a short and powerful statement. The purpose of an abstract is to provide prospective readers the opportunity to judge the relevance of the longer work to their projects. Abstracts also include the key terms found in the longer work and the purpose and methods of the research. Authors abstract various longer works, including book proposals, dissertations, and online journal articles. There are two main types of abstracts: descriptive and informative. A descriptive abstract briefly describes the longer work, while an informative abstract presents all the main arguments and important results. This handout provides examples of various types of abstracts and instructions on how to construct one.

Which type should I use?

Your best bet in this case is to ask your instructor or refer to the instructions provided by the publisher. You can also make a guess based on the length allowed; i.e., 100-120 words = descriptive; 250+ words = informative.

How do I write an abstract?

The format of your abstract will depend on the work being abstracted. An abstract of a scientific research paper will contain elements not found in an abstract of a literature article, and vice versa. However, all abstracts share several mandatory components, and there are also some optional parts that you can decide to include or not. When preparing to draft your abstract, keep the following key process elements in mind:

• Reason for writing: What is the importance of the research? Why would a reader be interested in the larger work?
• Problem: What problem does this work attempt to solve? What is the scope of the project? What is the main argument/thesis/claim?
• Methodology: An abstract of a scientific work may include specific models or approaches used in the larger study. Other abstracts may describe the types of evidence used in the research.
• Results: Again, an abstract of a scientific work may include specific data that indicates the results of the project. Other abstracts may discuss the findings in a more general way.
• Implications: What changes should be implemented as a result of the findings of the work? How does this work add to the body of knowledge on the topic?

(This list of elements is adapted with permission from Philip Koopman, “How to Write an Abstract.” )

All abstracts include:

• A full citation of the source, preceding the abstract.
• The most important information first.
• The same type and style of language found in the original, including technical language.
• Key words and phrases that quickly identify the content and focus of the work.
• Clear, concise, and powerful language.

Abstracts may include:

• The thesis of the work, usually in the first sentence.
• Background information that places the work in the larger body of literature.
• The same chronological structure as the original work.

How not to write an abstract:

• Do not refer extensively to other works.
• Do not add information not contained in the original work.
• Do not define terms.

If you are abstracting your own writing

When abstracting your own work, it may be difficult to condense a piece of writing that you have agonized over for weeks (or months, or even years) into a 250-word statement. There are some tricks that you could use to make it easier, however.

Reverse outlining:

This technique is commonly used when you are having trouble organizing your own writing. The process involves writing down the main idea of each paragraph on a separate piece of paper– see our short video . For the purposes of writing an abstract, try grouping the main ideas of each section of the paper into a single sentence. Practice grouping ideas using webbing or color coding .

For a scientific paper, you may have sections titled Purpose, Methods, Results, and Discussion. Each one of these sections will be longer than one paragraph, but each is grouped around a central idea. Use reverse outlining to discover the central idea in each section and then distill these ideas into one statement.

Cut and paste:

To create a first draft of an abstract of your own work, you can read through the entire paper and cut and paste sentences that capture key passages. This technique is useful for social science research with findings that cannot be encapsulated by neat numbers or concrete results. A well-written humanities draft will have a clear and direct thesis statement and informative topic sentences for paragraphs or sections. Isolate these sentences in a separate document and work on revising them into a unified paragraph.

If you are abstracting someone else’s writing

When abstracting something you have not written, you cannot summarize key ideas just by cutting and pasting. Instead, you must determine what a prospective reader would want to know about the work. There are a few techniques that will help you in this process:

Identify key terms:

Search through the entire document for key terms that identify the purpose, scope, and methods of the work. Pay close attention to the Introduction (or Purpose) and the Conclusion (or Discussion). These sections should contain all the main ideas and key terms in the paper. When writing the abstract, be sure to incorporate the key terms.

Highlight key phrases and sentences:

Instead of cutting and pasting the actual words, try highlighting sentences or phrases that appear to be central to the work. Then, in a separate document, rewrite the sentences and phrases in your own words.

Don’t look back:

After reading the entire work, put it aside and write a paragraph about the work without referring to it. In the first draft, you may not remember all the key terms or the results, but you will remember what the main point of the work was. Remember not to include any information you did not get from the work being abstracted.

Revise, revise, revise

No matter what type of abstract you are writing, or whether you are abstracting your own work or someone else’s, the most important step in writing an abstract is to revise early and often. When revising, delete all extraneous words and incorporate meaningful and powerful words. The idea is to be as clear and complete as possible in the shortest possible amount of space. The Word Count feature of Microsoft Word can help you keep track of how long your abstract is and help you hit your target length.

Example 1: Humanities abstract

Kenneth Tait Andrews, “‘Freedom is a constant struggle’: The dynamics and consequences of the Mississippi Civil Rights Movement, 1960-1984” Ph.D. State University of New York at Stony Brook, 1997 DAI-A 59/02, p. 620, Aug 1998

This dissertation examines the impacts of social movements through a multi-layered study of the Mississippi Civil Rights Movement from its peak in the early 1960s through the early 1980s. By examining this historically important case, I clarify the process by which movements transform social structures and the constraints movements face when they try to do so. The time period studied includes the expansion of voting rights and gains in black political power, the desegregation of public schools and the emergence of white-flight academies, and the rise and fall of federal anti-poverty programs. I use two major research strategies: (1) a quantitative analysis of county-level data and (2) three case studies. Data have been collected from archives, interviews, newspapers, and published reports. This dissertation challenges the argument that movements are inconsequential. Some view federal agencies, courts, political parties, or economic elites as the agents driving institutional change, but typically these groups acted in response to the leverage brought to bear by the civil rights movement. The Mississippi movement attempted to forge independent structures for sustaining challenges to local inequities and injustices. By propelling change in an array of local institutions, movement infrastructures had an enduring legacy in Mississippi.

Now let’s break down this abstract into its component parts to see how the author has distilled his entire dissertation into a ~200 word abstract.

What the dissertation does This dissertation examines the impacts of social movements through a multi-layered study of the Mississippi Civil Rights Movement from its peak in the early 1960s through the early 1980s. By examining this historically important case, I clarify the process by which movements transform social structures and the constraints movements face when they try to do so.

How the dissertation does it The time period studied in this dissertation includes the expansion of voting rights and gains in black political power, the desegregation of public schools and the emergence of white-flight academies, and the rise and fall of federal anti-poverty programs. I use two major research strategies: (1) a quantitative analysis of county-level data and (2) three case studies.

What materials are used Data have been collected from archives, interviews, newspapers, and published reports.

Conclusion This dissertation challenges the argument that movements are inconsequential. Some view federal agencies, courts, political parties, or economic elites as the agents driving institutional change, but typically these groups acted in response to movement demands and the leverage brought to bear by the civil rights movement. The Mississippi movement attempted to forge independent structures for sustaining challenges to local inequities and injustices. By propelling change in an array of local institutions, movement infrastructures had an enduring legacy in Mississippi.

Keywords social movements Civil Rights Movement Mississippi voting rights desegregation

Example 2: Science Abstract

Luis Lehner, “Gravitational radiation from black hole spacetimes” Ph.D. University of Pittsburgh, 1998 DAI-B 59/06, p. 2797, Dec 1998

The problem of detecting gravitational radiation is receiving considerable attention with the construction of new detectors in the United States, Europe, and Japan. The theoretical modeling of the wave forms that would be produced in particular systems will expedite the search for and analysis of detected signals. The characteristic formulation of GR is implemented to obtain an algorithm capable of evolving black holes in 3D asymptotically flat spacetimes. Using compactification techniques, future null infinity is included in the evolved region, which enables the unambiguous calculation of the radiation produced by some compact source. A module to calculate the waveforms is constructed and included in the evolution algorithm. This code is shown to be second-order convergent and to handle highly non-linear spacetimes. In particular, we have shown that the code can handle spacetimes whose radiation is equivalent to a galaxy converting its whole mass into gravitational radiation in one second. We further use the characteristic formulation to treat the region close to the singularity in black hole spacetimes. The code carefully excises a region surrounding the singularity and accurately evolves generic black hole spacetimes with apparently unlimited stability.

This science abstract covers much of the same ground as the humanities one, but it asks slightly different questions.

Why do this study The problem of detecting gravitational radiation is receiving considerable attention with the construction of new detectors in the United States, Europe, and Japan. The theoretical modeling of the wave forms that would be produced in particular systems will expedite the search and analysis of the detected signals.

What the study does The characteristic formulation of GR is implemented to obtain an algorithm capable of evolving black holes in 3D asymptotically flat spacetimes. Using compactification techniques, future null infinity is included in the evolved region, which enables the unambiguous calculation of the radiation produced by some compact source. A module to calculate the waveforms is constructed and included in the evolution algorithm.

Results This code is shown to be second-order convergent and to handle highly non-linear spacetimes. In particular, we have shown that the code can handle spacetimes whose radiation is equivalent to a galaxy converting its whole mass into gravitational radiation in one second. We further use the characteristic formulation to treat the region close to the singularity in black hole spacetimes. The code carefully excises a region surrounding the singularity and accurately evolves generic black hole spacetimes with apparently unlimited stability.

Keywords gravitational radiation (GR) spacetimes black holes

Works consulted

We consulted these works while writing this handout. This is not a comprehensive list of resources on the handout’s topic, and we encourage you to do your own research to find additional publications. Please do not use this list as a model for the format of your own reference list, as it may not match the citation style you are using. For guidance on formatting citations, please see the UNC Libraries citation tutorial . We revise these tips periodically and welcome feedback.

Belcher, Wendy Laura. 2009. Writing Your Journal Article in Twelve Weeks: A Guide to Academic Publishing Success. Thousand Oaks, CA: Sage Press.

Koopman, Philip. 1997. “How to Write an Abstract.” Carnegie Mellon University. October 1997. http://users.ece.cmu.edu/~koopman/essays/abstract.html .

Lancaster, F.W. 2003. Indexing And Abstracting in Theory and Practice , 3rd ed. London: Facet Publishing.

You may reproduce it for non-commercial use if you use the entire handout and attribute the source: The Writing Center, University of North Carolina at Chapel Hill

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How to Write an Abstract in Research Papers (with Examples)

An abstract in research papers is a keyword-rich summary usually not exceeding 200-350 words. It can be considered the “face” of research papers because it creates an initial impression on the readers. While searching databases (such as PubMed) for research papers, a title is usually the first selection criterion for readers. If the title matches their search criteria, then the readers read the abstract, which sets the tone of the paper. Titles and abstracts are often the only freely available parts of research papers on journal websites. The pdf versions of full articles need to be purchased. Journal reviewers are often provided with only the title and abstract before they agree to review the complete paper. [ 1]  

Abstracts in research papers provide readers with a quick insight into what the paper is about to help them decide whether they want to read it further or not. Abstracts are the main selling points of articles and therefore should be carefully drafted, accurately highlighting the important aspects. [ 2]  

This article will help you identify the important components and provide tips on how to write an abstract in research papers effectively

What is an Abstract?  

An abstract in research papers can be defined as a synopsis of the paper. It should be clear, direct, self-contained, specific, unbiased, and concise. These summaries are published along with the complete research paper and are also submitted to conferences for consideration for presentation.  

Abstracts are of four types and journals can follow any of these formats: [ 2]  

• Structured  
• Unstructured  
• Descriptive  
• Informative  

Structured abstracts are used by most journals because they are more organized and have clear sections, usually including introduction/background; objective; design, settings, and participants (or materials and methods); outcomes and measures; results; and conclusion. These headings may differ based on the journal or the type of paper. Clinical trial abstracts should include the essential items mentioned in the CONSORT (Consolidated Standards Of Reporting Trials) guidelines.  

Figure 1. Structured abstract example [3] 

Unstructured abstracts are common in social science, humanities, and physical science journals. They usually have one paragraph and no specific structure or subheadings. These abstracts are commonly used for research papers that don’t report original work and therefore have a more flexible and narrative style.  

Figure 2. Unstructured abstract example [3] 

Descriptive abstracts are short (75–150 words) and provide an outline with only the most important points of research papers. They are used for shorter articles such as case reports, reviews, and opinions where space is at a premium, and rarely for original investigations. These abstracts don’t present the results but mainly list the topics covered.  

Here’s a sample abstract . [ 4]  

“Design of a Radio-Based System for Distribution Automation”  

A new survey by the Maryland Public Utilities Commission suggests that utilities have not effectively explained to consumers the benefits of smart meters. The two-year study of 86,000 consumers concludes that the long-term benefits of smart meters will not be realized until consumers understand the benefits of shifting some of their power usage to off-peak hours in response to the data they receive from their meters. The study presents recommendations for utilities and municipal governments to improve customer understanding of how to use the smart meters effectively.  

Keywords: smart meters, distribution systems, load, customer attitudes, power consumption, utilities  

Informative abstracts (structured or unstructured) give a complete detailed summary, including the main results, of the research paper and may or may not have subsections.   

Figure 3. Informative abstract example [5] 

Purpose of Abstracts in Research    

Abstracts in research have two main purposes—selection and indexing. [ 6,7]  

• Selection : Abstracts allow interested readers to quickly decide the relevance of a paper to gauge if they should read it completely.   
• Indexing : Most academic journal databases accessed through libraries enable you to search abstracts, allowing for quick retrieval of relevant articles and avoiding unnecessary search results. Therefore, abstracts must necessarily include the keywords that researchers may use to search for articles.  

Thus, a well-written, keyword-rich abstract can p ique readers’ interest and curiosity and help them decide whether they want to read the complete paper. It can also direct readers to articles of potential clinical and research interest during an online search.  

Contents of Abstracts in Research  

Abstracts in research papers summarize the main points of an article and are broadly categorized into four or five sections. Here are some details on how to write an abstract .   

Introduction/Background and/or Objectives  

This section should provide the following information:  

• What is already known about the subject?  
• What is not known about the subject or what does the study aim to investigate?  

The hypothesis or research question and objectives should be mentioned here. The Background sets the context for the rest of the paper and its length should be short so that the word count could be saved for the Results or other information directly pertaining to the study. The objective should be written in present or past simple tense.  

Examples:  

The antidepressant efficacy of desvenlafaxine (DV) has been established in 8-week, randomized controlled trials. The present study examined the continued efficacy of DV across 6 months of maintenance treatment . [ 1]  

Objective: To describe gastric and breast cancer risk estimates for individuals with CDH1 variants.  

Design, Setting, and Participants (or Materials and Methods)  

This section should provide information on the processes used and should be written in past simple tense because the process is already completed.  

A few important questions to be answered include:  

• What was the research design and setting?  
• What was the sample size and how were the participants sampled?  
• What treatments did the participants receive?  
• What were the data collection and data analysis dates?  
• What was the primary outcome measure?  

Hazard ratios (HRs) were estimated for each cancer type and used to calculate cumulative risks and risks per decade of life up to age 80 years.  

This section, written in either present or past simple tense, should be the longest and should describe the main findings of the study. Here’s an example of how descriptive the sentences should be:  

Avoid: Response rates differed significantly between diabetic and nondiabetic patients.  

Better: The response rate was higher in nondiabetic than in diabetic patients (49% vs 30%, respectively; P<0.01).  

This section should include the following information:  

• Total number of patients (included, excluded [exclusion criteria])  
• Primary and secondary outcomes, expressed in words, and supported by numerical data  
• Data on adverse outcomes  

Example: [ 8]  

In total, 10.9% of students were reported to have favorable study skills. The minimum score was found for preparation for examination domain. Also, a significantly positive correlation was observed between students’ study skills and their Grade Point Average (GPA) of previous term (P=0.001, r=0.269) and satisfaction with study skills (P=0.001, r=0.493).  

Conclusions  

Here, authors should mention the importance of their findings and also the practical and theoretical implications, which would benefit readers referring to this paper for their own research. Present simple tense should be used here.  

Examples: [ 1,8]  

The 9.3% prevalence of bipolar spectrum disorders in students at an arts university is substantially higher than general population estimates. These findings strengthen the oft-expressed hypothesis linking creativity with affective psychopathology.  

The findings indicated that students’ study skills need to be improved. Given the significant relationship between study skills and GPA, as an index of academic achievement, and satisfaction, it is necessary to promote the students’ study skills. These skills are suggested to be reinforced, with more emphasis on weaker domains.  

When to Write an Abstract  

In addition to knowing how to write an abstract , you should also know when to write an abstract . It’s best to write abstracts once the paper is completed because this would make it easier for authors to extract relevant parts from every section.  

Abstracts are usually required for: [ 7]    

• submitting articles to journals  
• applying for research grants   
• writing book proposals  
• completing and submitting dissertations  
• submitting proposals for conference papers  

Mostly, the author of the entire work writes the abstract (the first author, in works with multiple authors). However, there are professional abstracting services that hire writers to draft abstracts of other people’s work.   

How to Write an Abstract (Step-by-Step Process)  

Here are some key steps on how to write an abstract in research papers: [ 9]  

• Write the abstract after you’ve finished writing your paper.  
• Select the major objectives/hypotheses and conclusions from your Introduction and Conclusion sections.  
• Select key sentences from your Methods section.  
• Identify the major results from the Results section.  
• Paraphrase or re-write the sentences selected in steps 2, 3, and 4 in your own words into one or two paragraphs in the following sequence: Introduction/Objective, Methods, Results, and Conclusions. The headings may differ among journals, but the content remains the same.  
• Ensure that this draft does not contain: a.   new information that is not present in the paper b.   undefined abbreviations c.   a discussion of previous literature or reference citations d.   unnecessary details about the methods used  
• Remove all extra information and connect your sentences to ensure that the information flows well, preferably in the following order: purpose; basic study design, methodology and techniques used; major findings; summary of your interpretations, conclusions, and implications. Use section headings for structured abstracts.  
• Ensure consistency between the information presented in the abstract and the paper.  
• Check to see if the final abstract meets the guidelines of the target journal (word limit, type of abstract, recommended subheadings, etc.) and if all the required information has been included.  

Choosing Keywords for Abstracts  

Keywords [ 2] are the important and repeatedly used words and phrases in research papers and can help indexers and search engines find papers relevant to your requirements. Easy retrieval would help in reaching a wider audience and eventually gain more citations. In the fields of medicine and health, keywords should preferably be chosen from the Medical Subject Headings (MeSH) list of the US National Library of Medicine because they are used for indexing. These keywords need to be different from the words in the main title (automatically used for indexing) but can be variants of the terms/phrases used in the title, abstract, and the main text. Keywords should represent the content of your manuscript and be specific to your subject area.  

Basic tips for authors [ 10,11]  

• Read through your paper and highlight key terms or phrases that are most relevant and frequently used in your field, to ensure familiarity.  
• Several journals provide instructions about the length (eg, 3 words in a keyword) and maximum number of keywords allowed and other related rules. Create a list of keywords based on these instructions and include specific phrases containing 2 to 4 words. A longer string of words would yield generic results irrelevant to your field.  
• Use abbreviations, acronyms, and initializations if these would be more familiar.  
• Search with your keywords to ensure the results fit with your article and assess how helpful they would be to readers.  
• Narrow down your keywords to about five to ten, to ensure accuracy.  
• Finalize your list based on the maximum number allowed.  

  Few examples: [ 12]  

Important Tips for Writing an Abstract  

Here are a few tips on how to write an abstract to ensure that your abstract is complete, concise, and accurate. [ 1,2]  

• Write the abstract last.  
• Follow journal-specific formatting guidelines or Instructions to Authors strictly to ensure acceptance for publication.  
• Proofread the final draft meticulously to avoid grammatical or typographical errors.  
• Ensure that the terms or data mentioned in the abstract are consistent with the main text.  
• Include appropriate keywords at the end.

Do not include:  

• New information  
• Text citations to references  
• Citations to tables and figures  
• Generic statements  
• Abbreviations unless necessary, like a trial or study name  

Key Takeaways    

Here’s a quick snapshot of all the important aspects of how to write an abstract . [2]

• An abstract in research is a summary of the paper and describes only the main aspects. Typically, abstracts are about 200-350 words long.  
• Abstracts are of four types—structured, unstructured, descriptive, and informative.  
• Abstracts should be simple, clear, concise, independent, and unbiased (present both favorable and adverse outcomes).  
• They should adhere to the prescribed journal format, including word limits, section headings, number of keywords, fonts used, etc.  
• The terminology should be consistent with the main text.   
• Although the section heading names may differ for journals, every abstract should include a background and objective, analysis methods, primary results, and conclusions.  
• Nonstandard abbreviations, references, and URLs shouldn’t be included.  
• Only relevant and specific keywords should be used to ensure focused searches and higher citation frequency.  
• Abstracts should be written last after completing the main paper.  

Frequently Asked Questions   

Q1. Do all journals have different guidelines for abstracts?  

A1. Yes, all journals have their own specific guidelines for writing abstracts; a few examples are given in the following table. [ 6,13,14,15]  

Q2. What are the common mistakes to avoid when writing an abstract?  

A2. Listed below are a few mistakes that authors may make inadvertently while writing abstracts.  

• Copying sentences from the paper verbatim  

An abstract is a summary, which should be created by paraphrasing your own work or writing in your own words. Extracting sentences from every section and combining them into one paragraph cannot be considered summarizing.  

• Not adhering to the formatting guidelines  

Journals have special instructions for writing abstracts, such as word limits and section headings. These should be followed strictly to avoid rejections.  

• Not including the right amount of details in every section  

Both too little and too much information could discourage readers. For instance, if the Background has very little information, the readers may not get sufficient context to appreciate your research. Similarly, incomplete information in the Methods and a text-heavy Results section without supporting numerical data may affect the credibility of your research.  

• Including citations, standard abbreviations, and detailed measurements  

Typically, abstracts shouldn’t include these elements—citations, URLs, and abbreviations. Only nonstandard abbreviations are allowed or those that would be more familiar to readers than the expansions.  

• Including new information  

Abstracts should strictly include only the same information mentioned in the main text. Any new information should first be added to the text and then to the abstract only if necessary or if permitted by the word limit.  

• Not including keywords  

Keywords are essential for indexing and searching and should be included to increase the frequency of retrieval and citation.  

Q3. What is the difference between abstracts in research papers and conference abstracts? [16]  

A3. The table summarizes the main differences between research and conference abstracts.  

  Thus, abstracts are essential “trailers” that can market your research to a wide audience. The better and more complete the abstract the more are the chances of your paper being read and cited. By following our checklist and ensuring that all key elements are included, you can create a well-structured abstract that summarizes your paper accurately.  

References  

• Andrade C. How to write a good abstract for a scientific paper or conference presentation. Indian J Psychiatry . 2011; 53(2):172-175. Accessed June 14, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136027/  
• Tullu MS. Writing the title and abstract for a research paper: Being concise, precise, and meticulous is the key. 2019; 13(Suppl 1): S12-S17. Accessed June 14, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6398294/  
• Zawia J. Writing an Academic Paper? Get to know Abstracts vs. Structured Abstracts. Medium. Published October 16, 2023. Accessed June 16, 2024. https://medium.com/@jamala.zawia/writing-an-academic-paper-get-to-know-abstracts-vs-structured-abstracts-11ed86888367  
• Markel M and Selber S. Technical Communication, 12 th edition. 2018; pp. 482. Bedford/St Martin’s.  
• Abstracts. Arkansas State University. Accessed June 17, 2024. https://www.astate.edu/a/global-initiatives/online/a-state-online-services/online-writing-center/resources/How%20to%20Write%20an%20Abstract1.pdf  
• AMA Manual of Style. 11 th edition. Oxford University Press.  
• Writing an Abstract. The University of Melbourne. Accessed June 16, 2024. https://services.unimelb.edu.au/__data/assets/pdf_file/0007/471274/Writing_an_Abstract_Update_051112.pdf  
• 10 Good Abstract Examples that will Kickstart Your Brain. Kibin Essay Writing Blog. Published April 5, 2017. Accessed June 17, 2024. https://www.kibin.com/essay-writing-blog/10-good-abstract-examples/  
• A 10-step guide to make your research paper abstract more effective. Editage Insights. Published October 16, 2013. Accessed June 17, 2024. https://www.editage.com/insights/a-10-step-guide-to-make-your-research-paper-abstract-more-effective  
• Using keywords to write your title and abstract. Taylor & Francis Author Services. Accessed June 15, 2024. https://authorservices.taylorandfrancis.com/publishing-your-research/writing-your-paper/using-keywords-to-write-title-and-abstract/  
• How to choose and use keywords in research papers. Paperpal by Editage blog. Published March 10, 2023. Accessed June 17, 2024. https://paperpal.com/blog/researcher-resources/phd-pointers/how-to-choose-and-use-keywords-in-research-papers  
• Title, abstract and keywords. Springer. Accessed June 16, 2024. https://www.springer.com/it/authors-editors/authorandreviewertutorials/writing-a-journal-manuscript/title-abstract-and-keywords/10285522  
• Abstract and keywords guide. APA Style, 7 th edition. Accessed June 18, 2024. https://apastyle.apa.org/instructional-aids/abstract-keywords-guide.pdf  
• Abstract guidelines. American Society for Microbiology. Accessed June 18, 2024. https://asm.org/events/asm-microbe/present/abstract-guidelines  
• Guidelines for conference abstracts. The Lancet. Accessed June 16, 2024. https://www.thelancet.com/pb/assets/raw/Lancet/pdfs/Abstract_Guidelines_2013.pdf  
• Is a conference abstract the same as a paper abstract? Global Conference Alliance, Inc. Accessed June 18, 2024. https://globalconference.ca/is-a-conference-abstract-the-same-as-a-paper-abstract/  

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• How to Write a High-Quality Conference Paper

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• How to Write the First Draft of a Research Paper with Paperpal? 

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How to Write an Abstract APA Format

Saul McLeod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

Learn about our Editorial Process

Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

An APA abstract is a brief, comprehensive summary of the contents of an article, research paper, dissertation, or report.

It is written in accordance with the guidelines of the American Psychological Association (APA), which is a widely used format in social and behavioral sciences. 

An APA abstract summarizes, usually in one paragraph of between 150–250 words, the major aspects of a research paper or dissertation in a prescribed sequence that includes:

• The rationale: the overall purpose of the study, providing a clear context for the research undertaken.
• Information regarding the method and participants: including materials/instruments, design, procedure, and data analysis.
• Main findings or trends: effectively highlighting the key outcomes of the hypotheses.
• Interpretations and conclusion(s): solidify the implications of the research.
• Keywords related to the study: assist the paper’s discoverability in academic databases.

The abstract should stand alone, be “self-contained,” and make sense to the reader in isolation from the main article.

The purpose of the abstract is to give the reader a quick overview of the essential information before reading the entire article. The abstract is placed on its own page, directly after the title page and before the main body of the paper.

Although the abstract will appear as the very first part of your paper, it’s good practice to write your abstract after you’ve drafted your full paper, so that you know what you’re summarizing.

Note : This page reflects the latest version of the APA Publication Manual (i.e., APA 7), released in October 2019.

Structure of the Abstract

[NOTE: DO NOT separate the components of the abstract – it should be written as a single paragraph. This section is separated to illustrate the abstract’s structure.]

1) The Rationale

One or two sentences describing the overall purpose of the study and the research problem(s) you investigated. You are basically justifying why this study was conducted.

• What is the importance of the research?
• Why would a reader be interested in the larger work?
• For example, are you filling a gap in previous research or applying new methods to take a fresh look at existing ideas or data?
• Women who are diagnosed with breast cancer can experience an array of psychosocial difficulties; however, social support, particularly from a spouse, has been shown to have a protective function during this time. This study examined the ways in which a woman’s daily mood, pain, and fatigue, and her spouse’s marital satisfaction predict the woman’s report of partner support in the context of breast cancer.
• The current nursing shortage, high hospital nurse job dissatisfaction, and reports of uneven quality of hospital care are not uniquely American phenomena.
• Students with special educational needs and disabilities (SEND) are more likely to exhibit behavioral difficulties than their typically developing peers. The aim of this study was to identify specific risk factors that influence variability in behavior difficulties among individuals with SEND.

2) The Method

Information regarding the participants (number, and population). One or two sentences outlining the method, explaining what was done and how. The method is described in the present tense.

• Pretest data from a larger intervention study and multilevel modeling were used to examine the effects of women’s daily mood, pain, and fatigue and average levels of mood, pain, and fatigue on women’s report of social support received from her partner, as well as how the effects of mood interacted with partners’ marital satisfaction.
• This paper presents reports from 43,000 nurses from more than 700 hospitals in the United States, Canada, England, Scotland, and Germany in 1998–1999.
• The study sample comprised 4,228 students with SEND, aged 5–15, drawn from 305 primary and secondary schools across England. Explanatory variables were measured at the individual and school levels at baseline, along with a teacher-reported measure of behavior difficulties (assessed at baseline and the 18-month follow-up).

3) The Results

One or two sentences indicating the main findings or trends found as a result of your analysis. The results are described in the present or past tense.

• Results show that on days in which women reported higher levels of negative or positive mood, as well as on days they reported more pain and fatigue, they reported receiving more support. Women who, on average, reported higher levels of positive mood tended to report receiving more support than those who, on average, reported lower positive mood. However, average levels of negative mood were not associated with support. Higher average levels of fatigue but not pain were associated with higher support. Finally, women whose husbands reported higher levels of marital satisfaction reported receiving more partner support, but husbands’ marital satisfaction did not moderate the effect of women’s mood on support.
• Nurses in countries with distinctly different healthcare systems report similar shortcomings in their work environments and the quality of hospital care. While the competence of and relation between nurses and physicians appear satisfactory, core problems in work design and workforce management threaten the provision of care.
• Hierarchical linear modeling of data revealed that differences between schools accounted for between 13% (secondary) and 15.4% (primary) of the total variance in the development of students’ behavior difficulties, with the remainder attributable to individual differences. Statistically significant risk markers for these problems across both phases of education were being male, eligibility for free school meals, being identified as a bully, and lower academic achievement. Additional risk markers specific to each phase of education at the individual and school levels are also acknowledged.

4) The Conclusion / Implications

A brief summary of your conclusions and implications of the results, described in the present tense. Explain the results and why the study is important to the reader.

• For example, what changes should be implemented as a result of the findings of the work?
• How does this work add to the body of knowledge on the topic?

Implications of these findings are discussed relative to assisting couples during this difficult time in their lives.

• Resolving these issues, which are amenable to managerial intervention, is essential to preserving patient safety and care of consistently high quality.
• Behavior difficulties are affected by risks across multiple ecological levels. Addressing any one of these potential influences is therefore likely to contribute to the reduction in the problems displayed.

The above examples of abstracts are from the following papers:

Aiken, L. H., Clarke, S. P., Sloane, D. M., Sochalski, J. A., Busse, R., Clarke, H., … & Shamian, J. (2001). Nurses’ reports on hospital care in five countries . Health affairs, 20(3) , 43-53.

Boeding, S. E., Pukay-Martin, N. D., Baucom, D. H., Porter, L. S., Kirby, J. S., Gremore, T. M., & Keefe, F. J. (2014). Couples and breast cancer: Women’s mood and partners’ marital satisfaction predicting support perception . Journal of Family Psychology, 28(5) , 675.

Oldfield, J., Humphrey, N., & Hebron, J. (2017). Risk factors in the development of behavior difficulties among students with special educational needs and disabilities: A multilevel analysis . British journal of educational psychology, 87(2) , 146-169.

5) Keywords

APA style suggests including a list of keywords at the end of the abstract. This is particularly common in academic articles and helps other researchers find your work in databases.

Keywords in an abstract should be selected to help other researchers find your work when searching an online database. These keywords should effectively represent the main topics of your study. Here are some tips for choosing keywords:

Core Concepts: Identify the most important ideas or concepts in your paper. These often include your main research topic, the methods you’ve used, or the theories you’re discussing.

Specificity: Your keywords should be specific to your research. For example, suppose your paper is about the effects of climate change on bird migration patterns in a specific region. In that case, your keywords might include “climate change,” “bird migration,” and the region’s name.

Consistency with Paper: Make sure your keywords are consistent with the terms you’ve used in your paper. For example, if you use the term “adolescent” rather than “teen” in your paper, choose “adolescent” as your keyword, not “teen.”

Jargon and Acronyms: Avoid using too much-specialized jargon or acronyms in your keywords, as these might not be understood or used by all researchers in your field.

Synonyms: Consider including synonyms of your keywords to capture as many relevant searches as possible. For example, if your paper discusses “post-traumatic stress disorder,” you might include “PTSD” as a keyword.

Remember, keywords are a tool for others to find your work, so think about what terms other researchers might use when searching for papers on your topic.

The Abstract SHOULD NOT contain:

Lengthy background or contextual information: The abstract should focus on your research and findings, not general topic background.

Undefined jargon, abbreviations,  or acronyms: The abstract should be accessible to a wide audience, so avoid highly specialized terms without defining them.

Citations: Abstracts typically do not include citations, as they summarize original research.

Incomplete sentences or bulleted lists: The abstract should be a single, coherent paragraph written in complete sentences.

New information not covered in the paper: The abstract should only summarize the paper’s content.

Subjective comments or value judgments: Stick to objective descriptions of your research.

Excessive details on methods or procedures: Keep descriptions of methods brief and focused on main steps.

Speculative or inconclusive statements: The abstract should state the research’s clear findings, not hypotheses or possible interpretations.

• Any illustration, figure, table, or references to them . All visual aids, data, or extensive details should be included in the main body of your paper, not in the abstract. 
• Elliptical or incomplete sentences should be avoided in an abstract . The use of ellipses (…), which could indicate incomplete thoughts or omitted text, is not appropriate in an abstract.

APA Style for Abstracts

An APA abstract must be formatted as follows:

Include the running head aligned to the left at the top of the page (professional papers only) and page number. Note, student papers do not require a running head. On the first line, center the heading “Abstract” and bold (do not underlined or italicize). Do not indent the single abstract paragraph (which begins one line below the section title). Double-space the text. Use Times New Roman font in 12 pt. Set one-inch (or 2.54 cm) margins. If you include a “keywords” section at the end of the abstract, indent the first line and italicize the word “Keywords” while leaving the keywords themselves without any formatting.

Example APA Abstract Page

Download this example as a PDF

Further Information

• APA 7th Edition Abstract and Keywords Guide
• Example APA Abstract
• How to Write a Good Abstract for a Scientific Paper or Conference Presentation
• How to Write a Lab Report
• Writing an APA paper

How long should an APA abstract be?

An APA abstract should typically be between 150 to 250 words long. However, the exact length may vary depending on specific publication or assignment guidelines. It is crucial that it succinctly summarizes the essential elements of the work, including purpose, methods, findings, and conclusions.

Where does the abstract go in an APA paper?

In an APA formatted paper, the abstract is placed on its own page, directly after the title page and before the main body of the paper. It’s typically the second page of the document. It starts with the word “Abstract” (centered and not in bold) at the top of the page, followed by the text of the abstract itself.

What are the 4 C’s of abstract writing?

The 4 C’s of abstract writing are an approach to help you create a well-structured and informative abstract. They are:

Conciseness: An abstract should briefly summarize the key points of your study. Stick to the word limit (typically between 150-250 words for an APA abstract) and avoid unnecessary details.

Clarity: Your abstract should be easy to understand. Avoid jargon and complex sentences. Clearly explain the purpose, methods, results, and conclusions of your study.

Completeness: Even though it’s brief, the abstract should provide a complete overview of your study, including the purpose, methods, key findings, and your interpretation of the results.

Cohesion: The abstract should flow logically from one point to the next, maintaining a coherent narrative about your study. It’s not just a list of disjointed elements; it’s a brief story of your research from start to finish.

What is the abstract of a psychology paper?

An abstract in a psychology paper serves as a snapshot of the paper, allowing readers to quickly understand the purpose, methodology, results, and implications of the research without reading the entire paper. It is generally between 150-250 words long.

How to craft an APA abstract

Last updated

16 December 2023

Reviewed by

An APA abstract is a brief but thorough summary of a scientific paper. It gives readers a clear overview of what the paper is about and what it intends to prove.

The purpose of an abstract is to allow researchers to quickly understand the paper's topic and purpose so they can decide whether it will be useful to them.

• What is the APA style?

APA style is a method of formatting and documentation used by the American Psychological Association. This style is used primarily for papers in the field of education and in the social sciences, including:

Anthropology

What is an abstract in APA format?

Writing an abstract in APA format requires you to conform to the writing rules for APA-style papers, including the following guidelines:

The abstract should be 150–250 words

It should be brief but concise, containing all the paper's main points

The abstract is a separate page that comes after the title page and before the paper's main content

• Key elements of an APA abstract 

While the rules for constructing an APA abstract are straightforward, the process can be challenging. You need to pack a great deal of relevant content into a short piece.

The essential elements of an APA abstract are:

Running header containing the title of the paper and page number

Section label, centered and in bold, containing the word "abstract"

The main content of the abstract, 150–250 words in length and double-spaced

A list of keywords, indented and introduced with the word "keywords" in italics

Essential points to cover in an APA abstract  

When you’re creating your APA abstract, consider the following questions.

What is the main topic the paper is addressing?

People searching for research on your topic will probably be browsing many papers and studies. The way your abstract is crafted will help to determine whether they feel your paper is worth reading.

Are your research methods quantitative or qualitative?

Quantitative research is focused on numbers and statistics, typically gathered from studies and polls where the questions are in yes/no or multiple-choice format.

Qualitative research is based on language and gathered using methods such as interviews and focus groups. It is more detailed and time-consuming to gather than quantitative research but can yield more complex and nuanced results.

Did you use primary or secondary sources?

Another key element is whether your research is based on primary or secondary sources. 

Primary research is data that you or your research team gathered. Secondary research is gathered from existing sources, such as databases or previously published studies.

Is your research descriptive or experimental?

Your research may be descriptive, experimental, or both.

With descriptive research , you’re describing or analyzing existing studies or theories on the topic. You may be using surveys, case studies, or observation to study the topic.

Experimental research studies variables using the scientific method. With an experiment, your objective is to establish a cause-and-effect relationship between two variables (or show the lack of one).

What conclusion did you reach?

Readers will want to know upfront what your paper is claiming or proving. Your APA abstract should give them a condensed version of your conclusions. Summarize your most significant findings.

It's customary to place your findings and conclusion in the final sentence of the abstract. This should be directly related to the main topic of the paper.

What is the relevance of your findings?

Show readers that your paper is a significant contribution to the field. While staying accurate and not overstating your case, boast a bit about why people need to read your paper.

Briefly describe the implications and importance of your findings. You can also point out any further research that is needed concerning this topic.

Did you choose the most appropriate keywords?

Including keywords is useful for indexing if your paper is eventually included in a database. Choose keywords that are relevant to the paper and as specific as possible.

For example, if your paper is about signs of learning disabilities in elementary-age children, your keyword list might include:

Learning disability symptoms

Elementary education

Language-based learning disabilities

Any other terms discussed in the paper

• How to format an APA abstract

Use standard APA formatting with double spacing, 12pt Times New Roman font, and one-inch margins.

Place a running head at the top left-hand side of the page. This is an abbreviated version of the paper's title. Use all capital letters for the running header. This is not usually required for academic papers but is essential if you are submitting the paper for publication. The page number “2” should follow the running header (Page 1 is the title page).

Just under the running head, in the center, place the word "abstract."

Place your list of keywords at the end. The list should be indented and, according to APA guidelines, contain three to five keywords.

• What are the 3 types of abstracts?

There are certain variations in different types of APA abstracts. Here are three of the most common ones.

Experimental or lab report abstracts

An abstract for an experimental or lab report needs to communicate the key purpose and findings of the experiment. Include the following:

Purpose and importance of the experiment

Hypothesis of the experiment

Methods used to test the hypothesis

Summary of the results of the experiment, including whether you proved or rejected the hypothesis

Literature review abstracts

A literature review is a survey of published work on a work of literature. It may be part of a thesis, dissertation, or research paper .

The abstract for a literature review should contain:

A description of your purpose for covering the research topic

Your thesis statement

A description of the sources used in the review

Your conclusions based on the findings

Psychology lab reports

Psychology lab reports are part of the experiment report category. Psychology experiments, however, may contain distinctive elements.

Describe the goal or purpose of the experiment

If the experiment includes human subjects, describe them. Mention the number of participants and what demographic they fit

Describe any tools, equipment, or apparatus you used for the experiment. For example, some experiments use electroencephalography (EEG) to measure brain waves. You may have also used tools such as questionnaires , case studies , or naturalistic observation. Describe the procedure and parameters of the experiment.

Summarize your conclusions

• What not to include in an APA abstract

As this section is 250 words maximum, it's important to know what should not be included.

Avoid the following in an APA abstract:

Jargon, acronyms, or abbreviations

Citations. These should appear in the body of the paper.

Lengthy or secondary information. Keep it brief and stick to the main points. Readers should want to read your paper for more detailed information.

Opinions or subjective comments

Anything not covered in the paper

• Guidelines for writing an APA abstract

While an abstract is the shortest section of your paper, it is nevertheless one of the most important parts. It determines whether or not someone decides that the paper is worth reading or not. What follows are some guidelines to keep in mind when creating your APA abstract. 

Focus on your main point. Don't try to fit in multiple conclusions. The idea is to give readers a clear idea of what your main point or conclusion is. On a similar note, be explicit about the implications and significance of your findings. This is what will motivate people to read your paper.

Write the abstract last. Ensure the abstract accurately conveys the content and conclusions of your paper. You may want to start with a rough draft of the abstract, which you can use as an outline to guide you when writing your paper. If you do this, make sure you edit and update the abstract after the full paper is complete.

Proofread your abstract. As the abstract is short and the first part of the paper people will read, it's especially important to make it clear and free of spelling, grammatical, or factual errors. Ask someone in your field to read through it.

Write the abstract for a general audience. While the paper may be aimed at academics, scientists, or specialists in your field, the abstract should be accessible to a broad audience. Minimize jargon and acronyms. This will make the paper easier to find by people looking for information on the topic.

Choose your keywords with care. The more relevant keywords you include, the more searchable your paper will be. Look up papers on comparable topics for guidance.

Follow any specific guidelines that apply to your paper. Requirements for the abstract may differ slightly depending on the topic or guidelines set by a particular instructor or publication.

APA style is commonly used in the fields of psychology, sociology, anthropology, economics, and education.

If you’re writing an abstract in APA style, there are certain conventions to follow. Your readers and people in your industry will expect you to adhere to particular elements of layout, content, and structure.

Follow our advice in this article, and you will be confident that your APA abstract complies with the expected standards and will encourage people to read your full paper.

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• Essential points to cover in an APA abstract

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How to write a good abstract for a scientific paper or conference presentation

Chittaranjan andrade.

Department of Psychopharmacology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India

Abstracts of scientific papers are sometimes poorly written, often lack important information, and occasionally convey a biased picture. This paper provides detailed suggestions, with examples, for writing the background, methods, results, and conclusions sections of a good abstract. The primary target of this paper is the young researcher; however, authors with all levels of experience may find useful ideas in the paper.

INTRODUCTION

This paper is the third in a series on manuscript writing skills, published in the Indian Journal of Psychiatry . Earlier articles offered suggestions on how to write a good case report,[ 1 ] and how to read, write, or review a paper on randomized controlled trials.[ 2 , 3 ] The present paper examines how authors may write a good abstract when preparing their manuscript for a scientific journal or conference presentation. Although the primary target of this paper is the young researcher, it is likely that authors with all levels of experience will find at least a few ideas that may be useful in their future efforts.

The abstract of a paper is the only part of the paper that is published in conference proceedings. The abstract is the only part of the paper that a potential referee sees when he is invited by an editor to review a manuscript. The abstract is the only part of the paper that readers see when they search through electronic databases such as PubMed. Finally, most readers will acknowledge, with a chuckle, that when they leaf through the hard copy of a journal, they look at only the titles of the contained papers. If a title interests them, they glance through the abstract of that paper. Only a dedicated reader will peruse the contents of the paper, and then, most often only the introduction and discussion sections. Only a reader with a very specific interest in the subject of the paper, and a need to understand it thoroughly, will read the entire paper.

Thus, for the vast majority of readers, the paper does not exist beyond its abstract. For the referees, and the few readers who wish to read beyond the abstract, the abstract sets the tone for the rest of the paper. It is therefore the duty of the author to ensure that the abstract is properly representative of the entire paper. For this, the abstract must have some general qualities. These are listed in Table 1 .

General qualities of a good abstract

SECTIONS OF AN ABSTRACT

Although some journals still publish abstracts that are written as free-flowing paragraphs, most journals require abstracts to conform to a formal structure within a word count of, usually, 200–250 words. The usual sections defined in a structured abstract are the Background, Methods, Results, and Conclusions; other headings with similar meanings may be used (eg, Introduction in place of Background or Findings in place of Results). Some journals include additional sections, such as Objectives (between Background and Methods) and Limitations (at the end of the abstract). In the rest of this paper, issues related to the contents of each section will be examined in turn.

This section should be the shortest part of the abstract and should very briefly outline the following information:

• What is already known about the subject, related to the paper in question
• What is not known about the subject and hence what the study intended to examine (or what the paper seeks to present)

In most cases, the background can be framed in just 2–3 sentences, with each sentence describing a different aspect of the information referred to above; sometimes, even a single sentence may suffice. The purpose of the background, as the word itself indicates, is to provide the reader with a background to the study, and hence to smoothly lead into a description of the methods employed in the investigation.

Some authors publish papers the abstracts of which contain a lengthy background section. There are some situations, perhaps, where this may be justified. In most cases, however, a longer background section means that less space remains for the presentation of the results. This is unfortunate because the reader is interested in the paper because of its findings, and not because of its background.

A wide variety of acceptably composed backgrounds is provided in Table 2 ; most of these have been adapted from actual papers.[ 4 – 9 ] Readers may wish to compare the content in Table 2 with the original abstracts to see how the adaptations possibly improve on the originals. Note that, in the interest of brevity, unnecessary content is avoided. For instance, in Example 1 there is no need to state “The antidepressant efficacy of desvenlafaxine (DV), a dual-acting antidepressant drug , has been established…” (the unnecessary content is italicized).

Examples of the background section of an abstract

The methods section is usually the second-longest section in the abstract. It should contain enough information to enable the reader to understand what was done, and how. Table 3 lists important questions to which the methods section should provide brief answers.

Questions regarding which information should ideally be available in the methods section of an abstract

Carelessly written methods sections lack information about important issues such as sample size, numbers of patients in different groups, doses of medications, and duration of the study. Readers have only to flip through the pages of a randomly selected journal to realize how common such carelessness is.

Table 4 presents examples of the contents of accept-ably written methods sections, modified from actual publications.[ 10 , 11 ] Readers are invited to take special note of the first sentence of each example in Table 4 ; each is packed with detail, illustrating how to convey the maximum quantity of information with maximum economy of word count.

Examples of the methods section of an abstract

The results section is the most important part of the abstract and nothing should compromise its range and quality. This is because readers who peruse an abstract do so to learn about the findings of the study. The results section should therefore be the longest part of the abstract and should contain as much detail about the findings as the journal word count permits. For example, it is bad writing to state “Response rates differed significantly between diabetic and nondiabetic patients.” A better sentence is “The response rate was higher in nondiabetic than in diabetic patients (49% vs 30%, respectively; P <0.01).”

Important information that the results should present is indicated in Table 5 . Examples of acceptably written abstracts are presented in Table 6 ; one of these has been modified from an actual publication.[ 11 ] Note that the first example is rather narrative in style, whereas the second example is packed with data.

Information that the results section of the abstract should ideally present

Examples of the results section of an abstract

CONCLUSIONS

This section should contain the most important take-home message of the study, expressed in a few precisely worded sentences. Usually, the finding highlighted here relates to the primary outcome measure; however, other important or unexpected findings should also be mentioned. It is also customary, but not essential, for the authors to express an opinion about the theoretical or practical implications of the findings, or the importance of their findings for the field. Thus, the conclusions may contain three elements:

• The primary take-home message
• The additional findings of importance
• The perspective

Despite its necessary brevity, this section has the most impact on the average reader because readers generally trust authors and take their assertions at face value. For this reason, the conclusions should also be scrupulously honest; and authors should not claim more than their data demonstrate. Hypothetical examples of the conclusions section of an abstract are presented in Table 7 .

Examples of the conclusions section of an abstract

MISCELLANEOUS OBSERVATIONS

Citation of references anywhere within an abstract is almost invariably inappropriate. Other examples of unnecessary content in an abstract are listed in Table 8 .

Examples of unnecessary content in a abstract

It goes without saying that whatever is present in the abstract must also be present in the text. Likewise, whatever errors should not be made in the text should not appear in the abstract (eg, mistaking association for causality).

As already mentioned, the abstract is the only part of the paper that the vast majority of readers see. Therefore, it is critically important for authors to ensure that their enthusiasm or bias does not deceive the reader; unjustified speculations could be even more harmful. Misleading readers could harm the cause of science and have an adverse impact on patient care.[ 12 ] A recent study,[ 13 ] for example, concluded that venlafaxine use during the second trimester of pregnancy may increase the risk of neonates born small for gestational age. However, nowhere in the abstract did the authors mention that these conclusions were based on just 5 cases and 12 controls out of the total sample of 126 cases and 806 controls. There were several other serious limitations that rendered the authors’ conclusions tentative, at best; yet, nowhere in the abstract were these other limitations expressed.

As a parting note: Most journals provide clear instructions to authors on the formatting and contents of different parts of the manuscript. These instructions often include details on what the sections of an abstract should contain. Authors should tailor their abstracts to the specific requirements of the journal to which they plan to submit their manuscript. It could also be an excellent idea to model the abstract of the paper, sentence for sentence, on the abstract of an important paper on a similar subject and with similar methodology, published in the same journal for which the manuscript is slated.

Source of Support: Nil

Conflict of Interest: None declared.

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How to Write an Abstract for a Research Paper | Examples

What is a research paper abstract?

Research paper abstracts summarize your study quickly and succinctly to journal editors and researchers and prompt them to read further. But with the ubiquity of online publication databases, writing a compelling abstract is even more important today than it was in the days of bound paper manuscripts.

Abstracts exist to “sell”  your work, and they could thus be compared to the “executive summary” of a business resume: an official briefing on what is most important about your research. Or the “gist” of your research. With the majority of academic transactions being conducted online, this means that you have even less time to impress readers–and increased competition in terms of other abstracts out there to read.

The APCI (Academic Publishing and Conferences International) notes that there are  12 questions or “points” considered in the selection process  for journals and conferences and stresses the importance of having an abstract that ticks all of these boxes. Because it is often the ONLY chance you have to convince readers to keep reading, it is important that you spend time and energy crafting an abstract that faithfully represents the central parts of your study and captivates your audience.

With that in mind, follow these suggestions when structuring and writing your abstract, and learn how exactly to put these ideas into a solid abstract that will captivate your target readers.

Before Writing Your Abstract

How long should an abstract be.

All abstracts are written with the same essential objective: to give a summary of your study. But there are two basic styles of abstract: descriptive and informative . Here is a brief delineation of the two:

Of the two types of abstracts, informative abstracts are much more common, and they are widely used for submission to journals and conferences. Informative abstracts apply to lengthier and more technical research and are common in the sciences, engineering, and psychology, while descriptive abstracts are more likely used in humanities and social science papers. The best method of determining which abstract type you need to use is to follow the instructions for journal submissions and to read as many other published articles in those journals as possible.

Research Abstract Guidelines and Requirements

As any article about research writing will tell you, authors must always closely follow the specific guidelines and requirements indicated in the Guide for Authors section of their target journal’s website. The same kind of adherence to conventions should be applied to journal publications, for consideration at a conference, and even when completing a class assignment.

Each publisher has particular demands when it comes to formatting and structure. Here are some common questions addressed in the journal guidelines:

• Is there a maximum or minimum word/character length?
• What are the style and formatting requirements?
• What is the appropriate abstract type?
• Are there any specific content or organization rules that apply?

There are of course other rules to consider when composing a research paper abstract. But if you follow the stated rules the first time you submit your manuscript, you can avoid your work being thrown in the “circular file” right off the bat.

Identify Your Target Readership

The main purpose of your abstract is to lead researchers to the full text of your research paper. In scientific journals, abstracts let readers decide whether the research discussed is relevant to their own interests or study. Abstracts also help readers understand your main argument quickly. Consider these questions as you write your abstract:

• Are other academics in your field the main target of your study?
• Will your study perhaps be useful to members of the general public?
• Do your study results include the wider implications presented in the abstract?

Outlining and Writing Your Abstract

What to include in an abstract.

Just as your  research paper title  should cover as much ground as possible in a few short words, your abstract must cover  all  parts of your study in order to fully explain your paper and research. Because it must accomplish this task in the space of only a few hundred words, it is important not to include ambiguous references or phrases that will confuse the reader or mislead them about the content and objectives of your research. Follow these  dos  and  don’ts  when it comes to what kind of writing to include:

• Avoid acronyms or abbreviations since these will need to be explained in order to make sense to the reader, which takes up valuable abstract space. Instead, explain these terms in the Introduction section of the main text.
• Only use references to people or other works if they are well-known. Otherwise, avoid referencing anything outside of your study in the abstract.
• Never include tables, figures, sources, or long quotations in your abstract; you will have plenty of time to present and refer to these in the body of your paper.

Use keywords in your abstract to focus your topic

A vital search tool is the research paper keywords section, which lists the most relevant terms directly underneath the abstract. Think of these keywords as the “tubes” that readers will seek and enter—via queries on databases and search engines—to ultimately land at their destination, which is your paper. Your abstract keywords should thus be words that are commonly used in searches but should also be highly relevant to your work and found in the text of your abstract. Include 5 to 10 important words or short phrases central to your research in both the abstract and the keywords section.

For example, if you are writing a paper on the prevalence of obesity among lower classes that crosses international boundaries, you should include terms like “obesity,” “prevalence,” “international,” “lower classes,” and “cross-cultural.” These are terms that should net a wide array of people interested in your topic of study. Look at our nine rules for choosing keywords for your research paper if you need more input on this.

Research Paper Abstract Structure

As mentioned above, the abstract (especially the informative abstract) acts as a surrogate or synopsis of your research paper, doing almost as much work as the thousands of words that follow it in the body of the main text. In the hard sciences and most social sciences, the abstract includes the following sections and organizational schema.

Each section is quite compact—only a single sentence or two, although there is room for expansion if one element or statement is particularly interesting or compelling. As the abstract is almost always one long paragraph, the individual sections should naturally merge into one another to create a holistic effect. Use the following as a checklist to ensure that you have included all of the necessary content in your abstract.

1) Identify your purpose and motivation

So your research is about rabies in Brazilian squirrels. Why is this important? You should start your abstract by explaining why people should care about this study—why is it significant to your field and perhaps to the wider world? And what is the exact purpose of your study; what are you trying to achieve? Start by answering the following questions:

• What made you decide to do this study or project?
• Why is this study important to your field or to the lay reader?
• Why should someone read your entire article?

In summary, the first section of your abstract should include the importance of the research and its impact on related research fields or on the wider scientific domain.

2) Explain the research problem you are addressing

Stating the research problem that your study addresses is the corollary to why your specific study is important and necessary. For instance, even if the issue of “rabies in Brazilian squirrels” is important, what is the problem—the “missing piece of the puzzle”—that your study helps resolve?

You can combine the problem with the motivation section, but from a perspective of organization and clarity, it is best to separate the two. Here are some precise questions to address:

• What is your research trying to better understand or what problem is it trying to solve?
• What is the scope of your study—does it try to explain something general or specific?
• What is your central claim or argument?

3) Discuss your research approach

Your specific study approach is detailed in the Methods and Materials section .  You have already established the importance of the research, your motivation for studying this issue, and the specific problem your paper addresses. Now you need to discuss  how  you solved or made progress on this problem—how you conducted your research. If your study includes your own work or that of your team, describe that here. If in your paper you reviewed the work of others, explain this here. Did you use analytic models? A simulation? A double-blind study? A case study? You are basically showing the reader the internal engine of your research machine and how it functioned in the study. Be sure to:

• Detail your research—include methods/type of the study, your variables, and the extent of the work
• Briefly present evidence to support your claim
• Highlight your most important sources

4) Briefly summarize your results

Here you will give an overview of the outcome of your study. Avoid using too many vague qualitative terms (e.g, “very,” “small,” or “tremendous”) and try to use at least some quantitative terms (i.e., percentages, figures, numbers). Save your qualitative language for the conclusion statement. Answer questions like these:

• What did your study yield in concrete terms (e.g., trends, figures, correlation between phenomena)?
• How did your results compare to your hypothesis? Was the study successful?
• Where there any highly unexpected outcomes or were they all largely predicted?

5) State your conclusion

In the last section of your abstract, you will give a statement about the implications and  limitations of the study . Be sure to connect this statement closely to your results and not the area of study in general. Are the results of this study going to shake up the scientific world? Will they impact how people see “Brazilian squirrels”? Or are the implications minor? Try not to boast about your study or present its impact as  too  far-reaching, as researchers and journals will tend to be skeptical of bold claims in scientific papers. Answer one of these questions:

• What are the exact effects of these results on my field? On the wider world?
• What other kind of study would yield further solutions to problems?
• What other information is needed to expand knowledge in this area?

After Completing the First Draft of Your Abstract

Revise your abstract.

The abstract, like any piece of academic writing, should be revised before being considered complete. Check it for  grammatical and spelling errors  and make sure it is formatted properly.

Get feedback from a peer

Getting a fresh set of eyes to review your abstract is a great way to find out whether you’ve summarized your research well. Find a reader who understands research papers but is not an expert in this field or is not affiliated with your study. Ask your reader to summarize what your study is about (including all key points of each section). This should tell you if you have communicated your key points clearly.

In addition to research peers, consider consulting with a professor or even a specialist or generalist writing center consultant about your abstract. Use any resource that helps you see your work from another perspective.

Consider getting professional editing and proofreading

While peer feedback is quite important to ensure the effectiveness of your abstract content, it may be a good idea to find an academic editor  to fix mistakes in grammar, spelling, mechanics, style, or formatting. The presence of basic errors in the abstract may not affect your content, but it might dissuade someone from reading your entire study. Wordvice provides English editing services that both correct objective errors and enhance the readability and impact of your work.

Additional Abstract Rules and Guidelines

Write your abstract after completing your paper.

Although the abstract goes at the beginning of your manuscript, it does not merely introduce your research topic (that is the job of the title), but rather summarizes your entire paper. Writing the abstract last will ensure that it is complete and consistent with the findings and statements in your paper.

Keep your content in the correct order

Both questions and answers should be organized in a standard and familiar way to make the content easier for readers to absorb. Ideally, it should mimic the overall format of your essay and the classic “introduction,” “body,” and “conclusion” form, even if the parts are not neatly divided as such.

Write the abstract from scratch

Because the abstract is a self-contained piece of writing viewed separately from the body of the paper, you should write it separately as well. Never copy and paste direct quotes from the paper and avoid paraphrasing sentences in the paper. Using new vocabulary and phrases will keep your abstract interesting and free of redundancies while conserving space.

Don’t include too many details in the abstract

Again, the density of your abstract makes it incompatible with including specific points other than possibly names or locations. You can make references to terms, but do not explain or define them in the abstract. Try to strike a balance between being specific to your study and presenting a relatively broad overview of your work.

Wordvice Resources

If you think your abstract is fine now but you need input on abstract writing or require English editing services (including paper editing ), then head over to the Wordvice academic resources page, where you will find many more articles, for example on writing the Results , Methods , and Discussion sections of your manuscript, on choosing a title for your paper , or on how to finalize your journal submission with a strong cover letter .    

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Writing an abstract - a six point checklist (with samples)

Posted in: abstract , dissertations

The abstract is a vital part of any research paper. It is the shop front for your work, and the first stop for your reader. It should provide a clear and succinct summary of your study, and encourage your readers to read more. An effective abstract, therefore should answer the following questions:

• Why did you do this study or project?
• What did you do and how?
• What did you find?
• What do your findings mean?

So here's our run down of the key elements of a well-written abstract.

• Size - A succinct and well written abstract should be between approximately 100- 250 words.
• Background - An effective abstract usually includes some scene-setting information which might include what is already known about the subject, related to the paper in question (a few short sentences).
• Purpose  - The abstract should also set out the purpose of your research, in other words, what is not known about the subject and hence what the study intended to examine (or what the paper seeks to present).
• Methods - The methods section should contain enough information to enable the reader to understand what was done, and how. It should include brief details of the research design, sample size, duration of study, and so on.
• Results - The results section is the most important part of the abstract. This is because readers who skim an abstract do so to learn about the findings of the study. The results section should therefore contain as much detail about the findings as the journal word count permits.
• Conclusion - This section should contain the most important take-home message of the study, expressed in a few precisely worded sentences. Usually, the finding highlighted here relates to the primary outcomes of the study. However, other important or unexpected findings should also be mentioned. It is also customary, but not essential, to express an opinion about the theoretical or practical implications of the findings, or the importance of their findings for the field. Thus, the conclusions may contain three elements:
• The primary take-home message.
• Any additional findings of importance.
• Implications for future studies.

Example Abstract 2: Engineering Development and validation of a three-dimensional finite element model of the pelvic bone.

Abstract from: Dalstra, M., Huiskes, R. and Van Erning, L., 1995. Development and validation of a three-dimensional finite element model of the pelvic bone. Journal of biomechanical engineering, 117(3), pp.272-278.

And finally...  A word on abstract types and styles

Abstract types can differ according to subject discipline. You need to determine therefore which type of abstract you should include with your paper. Here are two of the most common types with examples.

Informative Abstract

The majority of abstracts are informative. While they still do not critique or evaluate a work, they do more than describe it. A good informative abstract acts as a surrogate for the work itself. That is, the researcher presents and explains all the main arguments and the important results and evidence in the paper. An informative abstract includes the information that can be found in a descriptive abstract [purpose, methods, scope] but it also includes the results and conclusions of the research and the recommendations of the author. The length varies according to discipline, but an informative abstract is usually no more than 300 words in length.

Descriptive Abstract A descriptive abstract indicates the type of information found in the work. It makes no judgements about the work, nor does it provide results or conclusions of the research. It does incorporate key words found in the text and may include the purpose, methods, and scope of the research. Essentially, the descriptive abstract only describes the work being summarised. Some researchers consider it an outline of the work, rather than a summary. Descriptive abstracts are usually very short, 100 words or less.

Adapted from Andrade C. How to write a good abstract for a scientific paper or conference presentation. Indian J Psychiatry. 2011 Apr;53(2):172-5. doi: 10.4103/0019-5545.82558. PMID: 21772657; PMCID: PMC3136027 .

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How to Write a Good Abstract: Four Essential Elements with Example

This article shall guide you on how to write a good abstract. It lists the four essential elements of a good abstract, ideal number of words, and tense. The article ends with an example abstract of a real-life study with a supplemental video related to the findings.

After finishing your research paper, thesis, or scientific paper, there is a need for you to write the abstract. How is the abstract written? What are the essential elements of a good abstract?

If this is your first time, or you don’t feel confident about writing your first abstract, these tips are handy. I provide an example to demonstrate how it works.

Table of Contents

Why write the abstract.

The information provided in the abstract must be sufficient to help the researcher decide whether the work is relevant to his or her interest or not. It should be brief but not lacking in essential elements to foster understanding of the research conducted. The abstract will also help the researcher decide whether to read the whole research paper or not.

Definition of an Abstract

An abstract is a summary of your research paper, thesis, or scientific paper. The abstract describes an unpublished or published research study in capsule form. It is a brief overview of the investigation so that researchers can comprehend the content of the research quickly. A good abstract is a mini-version of the whole research paper.

Four Essential Elements of a Good Abstract

So how should the abstract of a research paper be written so that readers will derive the maximum benefit from it?

1. Objective, aim, or purpose of the research paper

This part of the abstract mentions the study’s rationale. It states clearly the  objective , aim, or purpose of the study. It answers the question: “Why do we care about the issue?”

It states the problem statement or the central argument or  thesis statement . The relevance of the study in society is highlighted. Why did the researchers undertake the research? What is at stake?

2. Method or methodology that states the procedures used in the conduct of the study

This portion of the abstract tells us the perspective adopted by the researcher or researchers. It describes the types of evidence used.

The method or methodology part also mentions the key concepts, relevant keywords that make it distinct and searchable. It also describes the focus of the investigation, whether it is a group of people, a particular gender, race, community, environment, etc.

3. Results or major findings

This portion of the abstract summarizes the results or major findings of the study. It only states the significant results, most important ones, or highlights of the study in a sentence or a few sentences.

4. Principal conclusion

This part of the research abstract states the principal conclusion of the study. After obtaining the findings, what did the researchers conclude?

The conclusion, in particular, should be given special attention in writing the abstract. The conclusion should be well supported by the findings of the investigation; not a sweeping statement without any valid argument or evidence to back it up. 

Other considerations in writing the research abstract

As an academician, reading research abstracts that tell very little of the salient findings of the paper, particularly those behind a  paywall , causes frustration. I tend to think those abstracts work more as a marketing strategy rather than to disseminate important information.

In truth, we can’t afford to be  free riders  as reliable and rigorous scientific publication requires time, money, and effort to produce. A candidate paper for publication requires intensive  peer review , editing, and formatting to make it worthy of publication in reputable journals. But perhaps publishing companies also need to be reasonable in their charges as many reviewers give their services for free.

Finally, the references (e.g. name of author and date) should not be cited in the abstract unless the research paper involves an improvement or modification of a previously published method used by a researcher.

Number of Words

If you submit a paper for inclusion in a conference presentation, organizers usually limit its length from 250 to 300 words. It is possible, however, to capture the essence of the paper in a few sentences.

Hence, the challenge is how to make the research abstract as short as possible, without leaving out the essential elements, that will cause readers to read the paper. The abstract serves as a teaser, a taste of the pie for readers to decide whether they will read the whole piece.

Tense of the Abstract

The abstract is usually written in the past tense because the investigation has transpired. However, statement of facts in, say, the results and discussion and the conclusion, must be in the present tense.

Example of an Abstract

I provide an example of a good abstract abiding with the precepts advanced in this article. It is for you to judge if this meets your expectations.

Young children’s exposure to violent computer games

The example of an abstract given here is a real-life situation, as Dr. Perry Wilson reports in the following video.

Notice in the video that the study has its limitations. The participants, while young (8 to 12 years old), were conscious that they were observed in a university laboratory. This set-up may have affected their behavior.

Final Notes

Have your style by deviating a little from the convention. The point is, the abstract should be interesting enough such that readers will want to read your investigation, learn from it, or skip it because it’s not directly relevant to their interest.

©P. A. Regoniel 9 November 2021

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How to write learning objectives: 35 examples, researcher’s euphoria: discovering something new, harnessing ai in education: 5 practical applications, about the author, patrick regoniel, one response.

I am writing an abstract on “reduce the use of antibiotics in food”…..can you help me out?

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How to Write a Research Paper: Parts of the Paper

• Choosing Your Topic
• Citation & Style Guides This link opens in a new window
• Critical Thinking
• Evaluating Information
• Parts of the Paper
• Writing Tips from UNC-Chapel Hill
• Librarian Contact

Parts of the Research Paper Papers should have a beginning, a middle, and an end. Your introductory paragraph should grab the reader's attention, state your main idea, and indicate how you will support it. The body of the paper should expand on what you have stated in the introduction. Finally, the conclusion restates the paper's thesis and should explain what you have learned, giving a wrap up of your main ideas.

1. The Title The title should be specific and indicate the theme of the research and what ideas it addresses. Use keywords that help explain your paper's topic to the reader. Try to avoid abbreviations and jargon. Think about keywords that people would use to search for your paper and include them in your title.

2. The Abstract The abstract is used by readers to get a quick overview of your paper. Typically, they are about 200 words in length (120 words minimum to  250 words maximum). The abstract should introduce the topic and thesis, and should provide a general statement about what you have found in your research. The abstract allows you to mention each major aspect of your topic and helps readers decide whether they want to read the rest of the paper. Because it is a summary of the entire research paper, it is often written last. 

3. The Introduction The introduction should be designed to attract the reader's attention and explain the focus of the research. You will introduce your overview of the topic,  your main points of information, and why this subject is important. You can introduce the current understanding and background information about the topic. Toward the end of the introduction, you add your thesis statement, and explain how you will provide information to support your research questions. This provides the purpose and focus for the rest of the paper.

4. Thesis Statement Most papers will have a thesis statement or main idea and supporting facts/ideas/arguments. State your main idea (something of interest or something to be proven or argued for or against) as your thesis statement, and then provide your supporting facts and arguments. A thesis statement is a declarative sentence that asserts the position a paper will be taking. It also points toward the paper's development. This statement should be both specific and arguable. Generally, the thesis statement will be placed at the end of the first paragraph of your paper. The remainder of your paper will support this thesis.

Students often learn to write a thesis as a first step in the writing process, but often, after research, a writer's viewpoint may change. Therefore a thesis statement may be one of the final steps in writing. 

Examples of Thesis Statements from Purdue OWL

5. The Literature Review The purpose of the literature review is to describe past important research and how it specifically relates to the research thesis. It should be a synthesis of the previous literature and the new idea being researched. The review should examine the major theories related to the topic to date and their contributors. It should include all relevant findings from credible sources, such as academic books and peer-reviewed journal articles. You will want  to:

• Explain how the literature helps the researcher understand the topic.
• Try to show connections and any disparities between the literature.
• Identify new ways to interpret prior research.
• Reveal any gaps that exist in the literature.

More about writing a literature review. . .

6. The Discussion ​The purpose of the discussion is to interpret and describe what you have learned from your research. Make the reader understand why your topic is important. The discussion should always demonstrate what you have learned from your readings (and viewings) and how that learning has made the topic evolve, especially from the short description of main points in the introduction.Explain any new understanding or insights you have had after reading your articles and/or books. Paragraphs should use transitioning sentences to develop how one paragraph idea leads to the next. The discussion will always connect to the introduction, your thesis statement, and the literature you reviewed, but it does not simply repeat or rearrange the introduction. You want to: 

• Demonstrate critical thinking, not just reporting back facts that you gathered.
• If possible, tell how the topic has evolved over the past and give it's implications for the future.
• Fully explain your main ideas with supporting information.
• Explain why your thesis is correct giving arguments to counter points.

7. The Conclusion A concluding paragraph is a brief summary of your main ideas and restates the paper's main thesis, giving the reader the sense that the stated goal of the paper has been accomplished. What have you learned by doing this research that you didn't know before? What conclusions have you drawn? You may also want to suggest further areas of study, improvement of research possibilities, etc. to demonstrate your critical thinking regarding your research.

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Role of an Abstract in Research Paper With Examples

Why does one write an abstract? What is so intriguing about writing an abstract in research paper after writing a full length research paper? How do research paper abstracts or summaries help a researcher during research publishing? These are the most common and frequently pondered upon questions that early career researchers search answers for over the internet!

Table of Contents

What does Abstract mean in Research?

In Research, abstract is “a well-developed single paragraph which is approximately 250 words in length”. Furthermore, it is single-spaced single spaced. Abstract outlines all the parts of the paper briefly. Although the abstract is placed in the beginning of the research paper immediately after research title , the abstract is the last thing a researcher writes.

Why Is an Abstract Necessary in Research Paper?

Abstract is a concise academic text that –

• Helps the potential reader get the relevance of your research study for their own research
• Communicates your key findings for those who have time constraints in reading your paper
• And helps rank the article on search engines based on the keywords on academic databases.

Purpose of Writing an Abstract in Research

Abstracts are required for –

• Submission of articles to journals
• Application for research grants
• Completion and submission of thesis
• Submission of proposals for conference papers.

Aspects Included in an Abstract

The format of your abstract depends on the field of research, in which you are working. However, all abstracts broadly cover the following sections:

Reason for Writing

One can start with the importance of conducting their research study. Furthermore, you could start with a broader research question and address why would the reader be interested in that particular research question.

Research Problem

You could mention what problem the research study chooses to address. Moreover, you could elaborate about the scope of the project, the main argument, brief about thesis objective or what the study claims.

• Methodology

Furthermore, you could mention a line or two about what approach and specific models the research study uses in the scientific work. Some research studies may discuss the evidences in throughout the paper, so instead of writing about methodologies you could mention the types of evidence used in the research.

The scientific research aims to get the specific data that indicates the results of the project. Therefore, you could mention the results and discuss the findings in a broader and general way.

Finally, you could discuss how the research work contributes to the scientific society and adds knowledge on the topic. Also, you could specify if your findings or inferences could help future research and researchers.

Types of Abstracts

Based on the abstract content —, 1. descriptive.

This abstract in research paper is usually short (50-100 words). These abstracts have common sections, such as –

• Focus of research
• Overview of the study.

This type of research does not include detailed presentation of results and only mention results through a phrase without contributing numerical or statistical data . Descriptive abstracts guide readers on the nature of contents of the article.

2. Informative

This abstract gives the essence of what the report is about and it is usually about 200 words. These abstracts have common sections, such as –

• Aim or purpose

This abstract provides an accurate data on the contents of the work, especially on the results section.

Based on the writing format —

1. structured.

This type of abstract has a paragraph for each section: Introduction, Materials and Methods, Results, and Conclusion. Also, structured abstracts are often required for informative abstracts.

2. Semi-structured

A semi-structured abstract is written in only one paragraph, wherein each sentence corresponds to a section. Furthermore, all the sections mentioned in the structured abstract are present in the semi-structured abstract.

3. Non-structured

In a non-structured abstract there are no divisions between each section. The sentences are included in a single paragraph. This type of presentation is ideal for descriptive abstracts.

Examples of Abstracts

Abstract example 1: clinical research.

Neutralization of Omicron BA.1, BA.2, and BA.3 SARS-CoV-2 by 3 doses of BNT162b2 vaccine

Abstract: The newly emerged Omicron SARS-CoV-2 has several distinct sublineages including BA.1, BA.2, and BA.3. BA.1 accounts for the initial surge and is being replaced by BA.2, whereas BA.3 is at a low prevalence at this time. Here we report the neutralization of BNT162b2-vaccinated sera (collected 1 month after dose 3) against the three Omicron sublineages. To facilitate the neutralization testing, we have engineered the complete BA.1, BA.2, or BA.3 spike into an mNeonGreen USA-WA1/2020 SARS-CoV-2. All BNT162b2-vaccinated sera neutralize USA-WA1/2020, BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s with titers of >20; the neutralization geometric mean titers (GMTs) against the four viruses are 1211, 336, 300, and 190, respectively. Thus, the BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s are 3.6-, 4.0-, and 6.4-fold less efficiently neutralized than the USA-WA1/2020, respectively. Our data have implications in vaccine strategy and understanding the biology of Omicron sublineages.

Type of Abstract: Informative and non-structured

Abstract Example 2: Material Science and Chemistry

Breaking the nanoparticle’s dispersible limit via rotatable surface ligands

Abstract: Achieving versatile dispersion of nanoparticles in a broad range of solvents (e.g., water, oil, and biofluids) without repeatedly recourse to chemical modifications are desirable in optoelectronic devices, self-assembly, sensing, and biomedical fields. However, such a target is limited by the strategies used to decorate nanoparticle’s surface properties, leading to a narrow range of solvents for existing nanoparticles. Here we report a concept to break the nanoparticle’s dispersible limit via electrochemically anchoring surface ligands capable of sensing the surrounding liquid medium and rotating to adapt to it, immediately forming stable dispersions in a wide range of solvents (polar and nonpolar, biofluids, etc.). Moreover, the smart nanoparticles can be continuously electrodeposited in the electrolyte, overcoming the electrode surface-confined low throughput limitation of conventional electrodeposition methods. The anomalous dispersive property of the smart Ag nanoparticles enables them to resist bacteria secreted species-induced aggregation and the structural similarity of the surface ligands to that of the bacterial membrane assists them to enter the bacteria, leading to high antibacterial activity. The simple but massive fabrication process and the enhanced dispersion properties offer great application opportunities to the smart nanoparticles in diverse fields.

Type of Abstract: Descriptive and non-structured

Abstract Example 3: Clinical Toxicology

Evaluation of dexmedetomidine therapy for sedation in patients with toxicological events at an academic medical center

Introduction: Although clinical use of dexmedetomidine (DEX), an alpha2-adrenergic receptor agonist, has increased, its role in patients admitted to intensive care units secondary to toxicological sequelae has not been well established.

Objectives: The primary objective of this study was to describe clinical and adverse effects observed in poisoned patients receiving DEX for sedation.

Methods: This was an observational case series with retrospective chart review of poisoned patients who received DEX for sedation at an academic medical center. The primary endpoint was incidence of adverse effects of DEX therapy including bradycardia, hypotension, seizures, and arrhythmias. For comparison, vital signs were collected hourly for the 5 h preceding the DEX therapy and every hour during DEX therapy until the therapy ended. Additional endpoints included therapy duration; time within target Richmond Agitation Sedation Score (RASS); and concomitant sedation, analgesia, and vasopressor requirements.

Results: Twenty-two patients were included. Median initial and median DEX infusion rates were similar to the commonly used rates for sedation. Median heart rate was lower during the therapy (82 vs. 93 beats/minute, p < 0.05). Median systolic blood pressure before and during therapy was similar (111 vs. 109 mmHg, p = 0.745). Five patients experienced an adverse effect per study definitions during therapy. No additional adverse effects were noted. Median time within target RASS and duration of therapy was 6.5 and 44.5 h, respectively. Seventeen patients (77%) had concomitant use of other sedation and/or analgesia with four (23%) of these patients requiring additional agents after DEX initiation. Seven patients (32%) had concomitant vasopressor support with four (57%) of these patients requiring vasopressor support after DEX initiation.

Conclusion: Common adverse effects of DEX were noted in this study. The requirement for vasopressor support during therapy warrants further investigation into the safety of DEX in poisoned patients. Larger, comparative studies need to be performed before the use of DEX can be routinely recommended in poisoned patients.

Keywords: Adverse effects; Alpha2-adrenergic receptor agonist; Overdose; Safety.

Type of Abstract: Informative and structured .

How was your experience  writing an abstract? What type of abstracts have you written? Do write to us or leave a comment below.

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Five Elements to Include in Your Abstract

• Three Elements for a Proper Thesis Title
• Effective Strategies for Proofreading a Research Document

An abstract is usually about a page long and should give the whole picture of your research in terms of the literature review, methodology, results and conclusion. Readers user the abstract to quickly find out what your research is about. A well written abstract is critical to pull in readers so that they can open up and read your work. The five main elements to include in your abstract are stated below.

Introduction

This is the first part of the abstract, and should be brief and attractive to the reader at the same time. After reading a well written intro, the reader would be eager to read more.

Research significance

This usually answers the question: Why did you do this research?

Methodology

This usually answers the questions: What did you do? How did you do it?

This answers the question: What did you find out after doing the research? Or what are the advantages of your method based on the results?

This usually answers the question: What do your findings mean? What have you contributed?

Read the abstract carefully and try to eliminate any sentence that doesn’t fit into any of the categories above. Make sure all of your sentences contribute to explain the whole picture.

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Research on intercity railway subsidy mechanism optimization from the perspective of a government–company game model: a case study of henan intercity railway.

1. Introduction

2. literature review, 2.1. research on the optimization of the railway subsidy mechanism, 2.2. research on game and subsidy mechanism optimization, 2.3. summary, 3. materials and methods, 3.1. problem description, 3.2. model assumption, 3.3. performance subsidy, 3.4. model framework, 3.5. calculation of expected payoff, 3.6. expected payoff of governments, 3.7. expected payoff of railway companies, 3.8. expected payoff of social capitals, 3.9. conclusion and simplification, 4. results and discussion, 4.1. background, 4.2. simulation results without performance subsidy, 4.3. simulation results with performance subsidy, 4.4. sensitivity analysis and discussion, 5. conclusions and policy suggestion, 5.1. conclusions, 5.2. policy suggestions, author contributions, institutional review board statement, informed consent statement, data availability statement, acknowledgments, conflicts of interest.

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Yue, G.; Zhao, Z.; Dai, L.; Hu, H. Research on Intercity Railway Subsidy Mechanism Optimization from the Perspective of a Government–Company Game Model: A Case Study of Henan Intercity Railway. Sustainability 2024 , 16 , 7631. https://doi.org/10.3390/su16177631

Yue G, Zhao Z, Dai L, Hu H. Research on Intercity Railway Subsidy Mechanism Optimization from the Perspective of a Government–Company Game Model: A Case Study of Henan Intercity Railway. Sustainability . 2024; 16(17):7631. https://doi.org/10.3390/su16177631

Yue, Guoyong, Zijian Zhao, Lei Dai, and Hao Hu. 2024. "Research on Intercity Railway Subsidy Mechanism Optimization from the Perspective of a Government–Company Game Model: A Case Study of Henan Intercity Railway" Sustainability 16, no. 17: 7631. https://doi.org/10.3390/su16177631

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An overview of traditional and advanced methods to detect part defects in additive manufacturing processes

• Published: 02 September 2024

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• Vivek V. Bhandarkar 1 ,
• Harshal Y. Shahare 1 ,
• Anand Prakash Mall 1 &
• Puneet Tandon   ORCID: orcid.org/0000-0001-7146-023X 1  

Additive manufacturing (AM) or 3-dimensional (3D) printing processes have been adopted in several industrial sectors including aerospace, automotive, medical, architecture, arts and design, food, and construction for the past few decades due to their numerous advantages over other conventional subtractive manufacturing processes. However, some flaws and defects associated with 3D-printed components hinder its extensive adoption in industries. Therefore, real-time detection and elimination of these defects by analyzing the defects-causing process parameters is very important to obtain a defect-free final component. While global efforts are in progress to develop defect detection techniques with the rise of Industry 4.0, there is still a limited scope of comprehensive research that encapsulates various defect detection techniques in the AM sector on a global scale. Thus, this systematic review explores defects in parts manufactured via metallic and non-metallic AM processes. It covers traditional defect detection methods and extends to recent advanced machine learning (ML) and deep learning (DL) based techniques. The paper also delves into challenges associated with the implementation of ML and DL approaches for defect detection, providing a comprehensive understanding of the current state and future directions in AM research.

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Bhandarkar, V.V., Shahare, H.Y., Mall, A.P. et al. An overview of traditional and advanced methods to detect part defects in additive manufacturing processes. J Intell Manuf (2024). https://doi.org/10.1007/s10845-024-02483-3

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A multistrategy differential evolution algorithm combined with Latin hypercube sampling applied to a brain–computer interface to improve the effect of node displacement

• Hanjui Chang 1 , 2 ,
• Yue Sun 1 , 2 ,
• Shuzhou Lu 1 , 2 &
• Daiyao Lin 1 , 2  

Scientific Reports volume  14 , Article number:  20420 ( 2024 ) Cite this article

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• Biotechnology
• Computational biology and bioinformatics
• Energy science and technology
• Mathematics and computing

Injection molding is a common plastic processing technique that allows melted plastic to be injected into a mold through pressure to form differently shaped plastic parts. In injection molding, in-mold electronics (IME) can include various circuit components, such as sensors, amplifiers, and filters. These components can be injected into the mold to form a whole within the melted plastic and can therefore be very easily integrated into the molded part. The brain–computer interface (BCI) is a direct connection pathway between a human or animal brain and an external device. Through BCIs, individuals can use their own brain signals to control these components, enabling more natural and intuitive interactions. In addition, brain–computer interfaces can also be used to assist in medical treatments, such as controlling prosthetic limbs or helping paralyzed patients regain mobility. Brain–computer interfaces can be realized in two ways: invasively and noninvasively, and in this paper, we adopt a noninvasive approach. First, a helmet model is designed according to head shape, and second, a printed circuit film is made to receive EEG signals and an IME injection mold for the helmet plastic parts. In the electronic film, conductive ink is printed to connect each component. However, improper parameterization during the injection molding process can lead to node displacements and residual stress changes in the molded part, which can damage the circuits in the electronic film and affect its performance. Therefore, in this paper, the use of the BCI molding process to ensure that the node displacement reaches the optimal value is studied. Second, the multistrategy differential evolutionary algorithm is used to optimize the injection molding parameters in the process of brain–computer interface formation. The relationship between the injection molding parameters and the actual target value is investigated through Latin hypercubic sampling, and the optimized parameters are compared with the target parameters to obtain the optimal parameter combination. Under the optimal parameters, the node displacement can be optimized from 0.585 to 0.027 mm, and the optimization rate can reach 95.38%. Ultimately, by detecting whether the voltage difference between the output inputs is within the permissible range, the reliability of the brain–computer interface after node displacement optimization can be evaluated.

Introduction

The brain–computer interface (BCI) is a technology that directly connects the brain to external devices, allowing people to control computers, machinery, or other devices via electroencephalographic signals 1 . The field of brain–computer interfaces (BCIs) has undergone significant development over the past few decades, moving from speculative concepts to practical applications with far-reaching implications for health care, neuroscience, and human-computer interaction. The origins of BCI research can be traced back to the mid-twentieth century, when the first attempts were made to understand and utilize the electrical activity of the brain. These early attempts were largely experimental, focusing on basic neuroscience research and the development of rudimentary neurophysiological recording techniques.

In the 1990s and early 2000s, significant advances were made in computational power, signal processing algorithms, and machine learning techniques that allowed for more sophisticated analysis and interpretation of brain signals. The development of both invasive and noninvasive biometric identification (BCI) systems accelerated during this period, driven by growing interest in a variety of potential applications, including complementary therapies, neural network therapy, electroencephalography, and neural network analysis 2 .

In recent years, there has been a surge in interdisciplinary research and collaboration, blending insights from neuroscience, engineering, computer science, and clinical practice. This convergence has led to significant breakthroughs in understanding brain dynamics and improving the performance and usability of biometric (BCI) systems. Notable achievements include the development of more accurate and reliable signal acquisition methods 3 , enhanced real-time processing capabilities 4 , and innovative applications in neurorehabilitation, communications, and entertainment 5 .

The primary purpose of a BCI is to detect and quantify the brain signal characteristics of a user’s intentions and to translate these characteristics in real time into commands that control a device to execute the user’s intentions. To accomplish this, BCI systems typically consist of four sequential components: signal acquisition, feature extraction, feature conversion, and device output. These components are controlled by an operating protocol that defines details regarding the start and end times of operations, details of signal processing, nature of device commands, and supervision of performance. Effective operating protocols give BCI systems the flexibility to meet the specific needs of each user. Figure 1 illustrates the principles of BCI and the related application areas.

BCI composition, implementation process and application field.

Although current technologies make neuromodulation and neurostimulation possible, the complexity of the brain and the high degree of individual variation make complete control of the brain a great challenge 6 . Neuromodulation and neurostimulation techniques are primarily used to modulate brain activity, treat certain neurological disorders or improve certain cognitive functions, but these techniques do not allow for full control of all brain functions. The uncontrollable nature of the brain further emphasizes the importance of optimizing EEG signal acquisition devices to ensure the best possible signal quality and device reliability with the current state of the art 7 .

As BCI technology continues to advance, the development of dry electrodes and wireless integrated acquisition systems is driving a new generation of wearable, mobile electroencephalography (EEG) devices. In recent years, researchers have made significant progress in dry electrode thin-film technology 8 . First, dry electrodes do not require conductive adhesive, which greatly simplifies the process of using the device and enhances the user’s wearing experience. Second, the flexibility and thinness of the dry electrode film enables it to closely fit a scalp, improving signal stability and quality. Moreover, the sensors are integrated into the electronic film, and these sensors are distributed around the electrode array or at the gap to avoid affecting electrode signal acquisition 9 . This feature not only enhances the accuracy of signal acquisition but also reduces the discomfort and wearing pressure that may be associated with traditional electrodes.

When a dry electrode film is integrated into the injection molding process, it is critical to ensure the reliability of the wiring connections in the electronic film and the accuracy of the signal transmission 10 , 11 . The wiring within the electronic film is responsible for transmitting EEG signals, so any small displacement of nodes or change in volume shrinkage can result in signal distortion or interruption of transmission, which in turn can affect the overall performance of the device. During the injection molding process, nodes within the electronic film may be displaced due to material flow and mold pressure. Ensuring precise alignment of node locations is critical to maintaining the integrity and stability of the signal path. Research needs to develop rigorous process control programs to minimize node displacement and ensure the functional integrity of the circuitry. Volumetric shrinkage of materials during injection molding is an unavoidable phenomenon. Changes in volumetric shrinkage may lead to deformation of an electronic film or breakage of a circuit, affecting the reliability of signal transmission. By selecting suitable materials and optimizing injection parameters, volume shrinkage can be effectively controlled to ensure the dimensional accuracy and shape stability of electronic films.

In the manufacturing process of BCI, the node displacement refers to the node displacement caused by the uneven surface of the plastic parts due to improper parameter setting during the injection molding process of the IME electronic film. This displacement will directly affect the final performance and signal quality of BCI equipment. It is important to note that node displacement usually occurs during helmet manufacturing. After the BCI is made, there is no displacement between the electrode, coil and helmet. Therefore, any displacement caused by manufacturing errors will be fixed during the helmet manufacturing process.

The nodal displacement of IME films needs to be refined, as it affects the overall device performance and signal quality. Optimizing these shifts reduces manufacturing errors, improves device consistency and reliability, and ensures the accuracy and stability of the EEG signals received from the electrodes.

As shown in Fig. 2 , for all IME injection molded products, the displacement of the IME film may be caused by improper parameter setting or uneven surface of the plastic parts during injection molding. The graph represents the direction and shape of the node displacement through curves. The node displacement that occurs may be greater or less than the original value, affecting the overall performance. Node displacement refers to the displacement of the IME film relative to its initial position during injection molding, which can occur in multiple directions.

Node displacement change diagram.

To achieve the above objectives, in this paper, the LHS and MSDE algorithms are used for multiobjective optimization. LHS is an efficient sample generation method that can uniformly distribute sample points in multidimensional space to ensure comprehensive coverage of the parameter space and to improve the efficiency and accuracy of the optimization process. MSDE is a global optimization method based on evolutionary computation. The differential evolutionary (DE) algorithm searches for the optimal solution in the solution space by means of population evolution and a differential variation strategy. MSDE shows high optimization efficiency and robustness when dealing with complex multiobjective optimization problems and can efficiently find the optimal parameter combinations to satisfy multiple performance metrics. In this paper, we discuss the design principle and fabrication process of this technology in detail and its practical application in EEG signal acquisition, providing theoretical and technical support for the development of a new generation of wearable and mobile BCIs.

After injection molding is complete, the electronic film covers the surface of the line, providing an additional layer of protection. Due to the electronic film, friction between the scalp and the device, as well as the user’s head movements (e.g., head bobbing), will not cause displacement or damage to the line. The flexibility and durability of the electronic film not only enhances the comfort and longevity of the device but also ensures the stability and accuracy of signal transmission.

In summary, this study aims to ensure the high quality and reliability of electronic thin-film EEG signal acquisition devices by multiobjective optimization of parameters in the injection molding process through LHS and MSDE. In this paper, we discuss in detail the design principle, manufacturing process of this technology and its practical application in EEG signal acquisition. This provides theoretical and technical support for the development of a new generation of wearable and mobile EEG devices.

Literature review

Research progress in brain–computer interface technology.

With the continuous advancement of technology, brain–computer interfaces have gradually become a field of great interest, especially with the emergence of computer graphics and artificial intelligence. Brain–computer interface (BCI) and neurostimulation technologies have made remarkable progress in neuroscience and clinical applications.

In 2012, Nicolas-Alonso et al. 12 discussed the different electrophysiological control signals that determine user intent and can be detected in brain activity. First, some techniques for dealing with artifacts in control signals and improving performance are presented in the signal enhancement step. Second, a number of mathematical algorithms used in the feature extraction and classification steps, which convert information from control signals into commands to operate a computer or other device, are examined. Finally, an overview of the various BCI applications that control a range of devices is given.

In 2012, Hanson et al. 13 described the design of a high-side digital current-controlled bipolar microstimulator and the in vivo validation of the device. Electrical stimulation of nerve tissue is widely used as a tool in experimental neuroscience research and as a method for restoring neurological function in patients with sensory and motor disorders. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective way of inducing or modulating sensory perception, including vision and touch. ICMS also holds promise for brain–computer–brain interfaces (bmbi) by writing information directly into the brain.

In 2017, Jun et al. 14 designed, built and tested a new type of silicon probe, called a neural pixel, to meet this demand. The voltage signal is filtered, amplified, multiplexed and digitized, allowing noiseless digital data to be transmitted directly from the probe. The fully integrated functionality and small size of the neural pixel probes allow the recording of a large number of neurons from multiple brain structures in freely moving animals. This combination of high-performance electrode technology and scalable chip fabrication methods facilitates recording neural activity throughout the brain during a specific behavior.

In 2017, Yeon et al. 15 presented a feasibility study of wireless power and data transmission via inductive links to a 1 sq mm implant used as a free-floating neural probe distributed over areas of interest in the brain. The proposed structure uses a four-coil induction link for backward telemetry, which is shared with a three-coil link for wireless power transmission. A geometric optimization design method for an induction link based on the power transfer efficiency (PTE) is proposed, accounting for the specific absorption rate and the data rate. An active data transmission circuit based on low-power pulses is designed, and the performance of the proposed induction link is characterized in terms of the data rate and bit error rate.

In 2021, Zhou et al. 16 reviewed flexible thin-film devices, which can be divided into the following four categories: plane layout, open network layout, probe layout and microwire layout. The preparation methods are also introduced. Traditional lithography and the most advanced processing methods are discussed for the key problem of high resolution. For special substrates and interconnects, different materials and manufacturing processes are also emphasized. Finally, obstacles and directions for future research are discussed.

In 2021, Sun et al. 17 proposed an improved eddy current sensor drive circuit. To generate a stable oscillator source with high stability and good frequency accuracy, a quartz oscillator circuit with a power boost is used instead of the traditional Kolpitz oscillator circuit. The experimental results show that the designed eddy current sensor has good linearity (1.12%) and sensitivity (2.14 V/mm), which can ensure stable operation of the magnetic levitation turbomolecular pump at the rated speed.

In 2021, Hramov et al. 18 discussed the main results of the development and application of BCIs based on invasive and noninvasive EEG recordings. The new technological trend in the development of brain interfaces, namely, the use of neural interfaces to enhance human interaction, known as brain-to-brain interfaces (BBIs), is also discussed.

In 2022, Song et al. 19 presented an implantable pulsed UWB wireless telemetry system for neural sensing interfaces in the cortex. Three-dimensional hybrid pulse modulation is proposed, which consists of phase shift keying (PSK), pulse position modulation (PPM), and pulse amplitude modulation (PAM).

In 2022, Pei et al. 20 developed a Pregel electrode with a short installation time and good comfort for EEG acquisition. A hydrogel probe is preplaced on the Ag/AgCl electrodes prior to wearing the EEG headband rather than undergoing a time-consuming gel injection after wearing the headband.

In 2022, Yao et al. 21 developed a Pregel electrode with a short application time and good comfort for EEG recording. A hydrogel probe is pre-applied to the Ag/AgCl electrodes before the EEG headband is put on instead of a time-consuming gel injection after the headband is put on.

In 2023, Liu et al. 22 reviewed the preparation of nanomaterial-based MEAs for bidirectional in vitro BCIs from a multidisciplinary perspective. These researchers also considered the decoding and encoding of neural activity through the interface and highlighted the various uses of MEAs in combination with isolated neural cultures to benefit the future development of BCIs.

In summary, brain–computer interfaces and neurostimulation technologies have made significant progress in detection, signal processing, neural recording and wireless transmission. These studies have not only enriched our understanding of brain function but also provided strong technical support for neuroscience research and clinical applications. From enhancing electrophysiological signals to high-performance neural recording to wireless transmission and the application of flexible devices, a series of innovative technologies are driving the field of brain–computer interfaces forward. The collection of brain signals can be divided into invasive and noninvasive methods. In this paper, we use noninvasive methods to realize brain–computer interactions through IME in-mold electronic decoration technology, in which electrode films were combined to realize interface fabrication. The collected signals are feature extracted and classified and recognized using MEAs to increase the accuracy of signal collection and extraction from the brain–computer interface.

Research progress of electronic thin films

In recent years, there has been significant progress in electronic thin-film technology in a number of high-tech applications. Electronic thin films, especially those with integrated microelectrodes and sensors, have become an important means of realizing highly sensitive and accurate signal acquisition. Their ability to provide excellent mechanical strength and chemical stability, as well as good adhesion and waterproofing properties, makes them promising for a wide range of applications in medical, industrial and consumer electronics.

In 2014, Fukuda et al. 23 reported fully printed organic thin-film transistor devices and circuits fabricated on 1-mm-thick polystyrene-c films with high field-effect mobility and fast operation (~1 ms) at low operating voltages. These devices are also very lightweight and exhibit excellent mechanical stability. Even at 50% compressive strain, the devices remain operational with no significant change in performance.

In 2016, Petti et al. 24 presented the implementation of large-area digital circuits such as flexible near-field communication tags and analog integrated circuits such as bendable operational amplifiers. These include foldable displays, power transmission elements and integrated systems for large-area sensing and data storage and transmission.

In 2017, Mohammed et al. 25 demonstrated a fully automated printing process for flexible and stretchable electronics based on liquid metals. The printing process allows for the production of liquid metal-based sensors, and in addition, this printing process can produce complex conductive patterns that were not possible with previous nonautomated manufacturing methods.

In 2018, Wen 26 prepared a transparent and stretchable wrinkled poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) electrode-based TENG (WP-TENG) for use in human motion monitoring sensors.

In 2023, Zheng et al. 27 fabricated flexible transient circuits for human-computer interactions by printing liquid metal conductors on water-soluble electrospun silk films. Due to the inherent liquid conductor within the porous substrate, the circuits offer high resolution, custom pattern feasibility, attractive magnetic permeability, excellent conductivity, and superior mechanical stability.

Although these studies show that electronic thin films have great potential in terms of mechanical stability, flexibility, and conductive properties, optimizing the displacement of the nodes of electronic thin films remains a key issue in practical applications. The micrometer-scale lines of electrodes and sensors in thin films are susceptible to stress and deformation during fabrication and use, which in turn affects the accuracy of signal transmission and the overall performance of the device. Therefore, it is necessary to further study and optimize the displacement of these nodes to improve the reliability and stability of electronic thin films in complex application environments.

Research progress on optimization methods

Multiobjective optimization techniques are widely used for the optimal design and performance improvement of various complex systems. This paper reviews the multiobjective optimization methods applied in the fields of injection molding and BCI in recent years, especially the application of LHS and MSDE in these fields.

In 2013, Roshanian et al. 28 adopted the Latin hypercube sampling (LHS) method and assumed that the uncertain variables were normally distributed; this method was used to select the sample values of the simulation run and finally to compute the probability density function and reliability of the constraint at each design point. Sequential quadratic programming (SQP) was used to determine the optimal solution.

In 2016, Maschio et al. 29 described a new probabilistic history-matching iterative process hypercube (DLHC) sampling method with nonparametric density estimation using discrete Latin. The iterative process selects a set of models based on the quality of the historical fit (normalized disfit) to generate the histogram. The histogram is smoothed and used to estimate the marginal probability density of reservoir attributes.

In 2023, Chang et al. 30 proposed applying the Latin hypercube sampling method and combining the response surface model with the constraint generation inverse design network (CGIDN) to achieve multiobjective optimization of the injection process, shorten the time needed to find the optimal process parameters, and improve the production efficiency of plastic parts.

In 2015, Raza et al. 31 proposed a covariate offset detection and adaptation method and applied it to a BCI based on moving images. Covariate offset detection tests based on exponentially weighted moving average models are used to detect covariate offsets in features extracted from brain responses based on moving images. After the covariate offset detection test, the method initiates adaptivity by updating the classifier during the test/operation phase. The effectiveness of the proposed approach was evaluated using real BCI datasets, namely, the BCI Competition IV datasets 2A and 2B.

In 2018, Navid et al. 32 studied the Nelder‒Mead algorithm for diesel engine optimization, and the Sobol sequence and Latin hypercube sampling method for initial point distribution. The Nelder‒Mead algorithm is a non-evolutionary algorithm that requires some initial points to start the optimization process to understand the relationship between the input parameters and the output objective functions. In this study, these points were generated from Sobol sequences and Latin Hypercube sequences to compare the two types of sequences and to study the effect of the sequences on the results.

In 2020, Zhao et al. 33 proposed a new optimization strategy for the injection molding process, which transforms the problem of parameter optimization into a weight classification problem. Injection-molded parts are produced under different parameters and marked as positive or negative compared to the standard weight, and weight errors are calculated for each sample. A classification hyperplane with zero weight error is constructed using a support vector classifier (SVC). Particle swarm optimization (PSO) was used to adjust the hyperparameters of the SVC model to reduce the error between the SVC prediction results and the experimental results.

In 2020, Hao et al. 34 proposed a linear population size reduction adaptive differential evolution optimization algorithm (MSDE) based on a multistrategy success history. The proposed MSDE is superior to the existing algorithms in terms of accuracy, reliability and time consumption. The experimental results and analysis show that the MLSHADE algorithm is highly competitive in terms of accuracy and reliability.

In 2021, Niu et al. 35 proposed a new hybrid gravity search algorithm. The method uses the gravity search algorithm as a unified framework. The neighborhood search strategy is used to consider social information and individual experience to improve the convergence speed. An adaptive mutation strategy was adopted to improve population diversity through elite preservation and mutation operators. The improved elastic sphere strategy and constraint processing technique are used to improve the feasibility of solving the problem. The simulation results of the numerical functions demonstrate the proposed method.

In 2021, Peng et al. 36 proposed a new differential evolution algorithm, namely, multistrategy coevolutionary differential evolution (MSDE). In MVOPs, a mixed-variable coevolution scheme is adopted, which considers both continuous and discrete variables. Based on this, a multistrategy coevolution method is proposed that considers a dynamic adaptive selection mechanism and combines different feature mutation strategies and crossover operators to adapt to all-inclusive MVOPs. In addition, to improve the efficiency and flexibility of MSDE, a statistics-based local search (SBA) is proposed for discrete-variable optimization in MVOPs.

In 2022, Chang et al. 37 adopted the Pareto method to optimize the frame and injection molding process parameters to carry out multiobjective optimization of unmanned aerial vehicle (UAV) shell parts. The kriging function predicts the mathematical relationship among the die index and warp value and process parameters. Using LHD sampling and NSGA-II, a convergence curve of warp values is found near the Pareto optimal bound.

By reviewing the multiobjective optimization techniques in the field of injection molding and brain–computer interfaces in recent years, it can be seen that Latin hypercube sampling and multistrategy differential evolution algorithms have significant advantages in improving system performance and optimizing design. These studies not only provide effective methods and tools for multiobjective optimization of complex systems but also lay a solid foundation for future research and application.

Therefore, this paper proposes to investigate the node displacement of BCIs, which mainly focuses on optimizing the injection parameters to achieve the minimum change in node displacement to increase the accuracy of EEG signal transmission. Table 1 summarizes the reviewed literature by listing the individual articles on the study of node displacement in the brain–computer interface. In this paper, the importance of coil displacement is mainly studied. Previous studies 1 , 4 , 14 have mentioned that the overall framework structure of the brain–computer interface and node displacement affect the accuracy of the signal 1 . The optimization method is mentioned in 14 but is insufficient; therefore, this paper builds upon the above to further optimize using the LHS and MSDE methods.

In BCI-printed circuits, the thickness of the lines in the electronic film is usually at the micrometer level. This is because micron-level lines provide higher sensitivity and better spatial resolution for capturing and detecting EEG signals. In general, the width of the coils in a brain–computer interface is usually between a few microns and a few tens of microns. Optimizing nodal displacement and volume shrinkage is therefore particularly important for ensuring the quality of the electronic film. Since the line connections in electronic films experience thermal and mechanical stresses during the injection molding process, any undue node displacement or volume shrinkage can affect the accuracy of signal transmission. By optimizing these parameters, signal distortion and data errors due to inaccuracies in the manufacturing process can be reduced, thereby improving the overall performance and reliability of the BCI system.

Voltage detection is a key aspect in regard to the quality of BCI electronic films. According to a review of the literature, the multistrategy differential evolutionary algorithm has advantages over the NSGA-II in terms of efficiency and robustness. Furthermore, when dealing with complex problems in the injection molding process of the brain–computer interface, it can avoid local optimal solutions due to the irrationality of the parameters. According to the multistrategy approach of many researchers, to solve the problems of the traditional differential evolution algorithm, in this paper, mainly the multistrategy differential evolution algorithm is mainly utilized to find the optimal parameter combinations for the BCI.

In summary, many scholars have carried out many studies on the preparation of BCIs. According to the realization process of brain–computer interfaces, these interfaces are proposed by using in-mold electronic decoration technology, which sandwiches printed circuits between films to form an integrated organizational structure, avoiding problems such as shifting and instability of the electronic film nodes.

As shown in Fig. 3 , for the realization of BCIs, an innovative scheme is proposed to fabricate BCIs using in-mold electron decoration technology. Molecular sensor technology is introduced to monitor the minute displacements of nodes. The relationships between the injection molding parameters (melting temperature, holding pressure, and holding time) and the target parameters (node displacement and volume shrinkage) are thoroughly explored using LHS technology. By finding the optimal combination of parameters, the performance and reliability of the BCI are successfully improved. An improved multistrategy differential evolutionary algorithm is used to optimize the injection parameters, and the effectiveness of the optimized parameter combinations is verified via simulation.

BMI optimization experiment using MSDE.

Materials and methods

The selection of materials is carried out first. In 2015, Deng et al. 38 grew large-area graphene films on copper foil by using an R2R chemical vapor deposition process. These films were thermally laminated onto nanowire precoated ethylene vinyl acetate copolymer (EVA)/ethylene terephthalate (PET) films. The copper foil was preserved for reuse by R2R electrochemical layering. The packaging structure minimizes the wire-to-wire resistance and graphene grain boundary resistance and enhances the adhesion of nanowires and graphene to the plastic substrate, resulting in excellent photoelectric performance, corrosion resistance and mechanical flexibility. In 2010, Junxia et al. introduced a new process for the recycling of EVA and PET composite plastic films by improving the traditional floatation and sinking process to realize the continuous production of plastic separation and recycling.

To ensure that the BCI is comfortable and reliable, electrodes can be fabricated using PET plus surface EVA polymers. The PET film provides good mechanical strength and chemical stability, while the EVA polymers provide good adhesion and water resistance.

Therefore, PET and EVA were finally selected as the materials for the electronic film. The PET film was chosen for its good mechanical strength and chemical stability, which can effectively protect the internal circuits from external shocks and chemical corrosion. The EVA polymer material, on the other hand, provides excellent adhesion and water resistance to ensure the stability and reliability of the electronic film under different environmental conditions.

First, lines are printed on the PET film to create electrode connections. Minute electrode patterns are precisely formed on the surface of the PET film to ensure that the electrodes are aligned and connected as designed. In addition, the mechanical strength and chemical stability of the PET film make it an ideal substrate material for holding and protecting microelectrode arrays. Next, the PET film is coated with a layer of EVA polymer, which has excellent adhesion properties, adheres firmly to the PET film, and provides good water resistance to protect the electrodes from moisture and liquids. The flexibility of EVA also improves the overall flexibility of the electronic film, making it more suitable for use in head-worn devices. The prepared electronic film is then processed using injection molding electronics (IME) technology, which combines the electronic film with the injection molding material to form an integrated structure.

Liquid silicone rubber (LSR) was chosen as the injection molding material to ensure a comfortable wearing experience. LSR is a soft and flexible material that provides a good wearing experience, and its biocompatibility and durability make it an ideal material for head-worn devices 39 .

It can be seen that the EVA and PET polymer materials have good adhesion. In this paper, an EVA film layer is applied to the surface of a PET shell using in-mold electronic decoration technology to improve the safety and stability of a BCI. The IME membrane has good electrical properties and high transparency and can achieve efficient stimulation and monitoring of nerve tissue. Figure 3 shows the PVT diagram of the PET and EVA materials used in this work.

A pressure‒volume‒temperature (PVT) diagram is a diagram that describes the behavior of a material under different pressure, volume and temperature conditions. Specifically, the PVT diagram contains the following information: pressure (P), volume (V), and temperature (T).

As shown in Fig. 4 , the PET material has good chemical stability and mechanical strength to protect the electrode array and prevent signal loss. At the same time, the EVA polymer material can fill the gap between the electrodes, improving the efficiency of signal transmission.

Comparison of the PVTs of the PET and EVA images.

Second, the use of PET and EVA materials can effectively prevent the electrode array from being disturbed and damaged by the external environment and reduce artifacts caused by mechanical motion, thus improving the reliability of the BCI.

Finally, the use of IME technology to produce electrode arrays can realize high-precision and efficient manufacturing. Moreover, PET and EVA materials are also easy to process and manufacture, making the entire production process simpler and more controllable.

• Latin hypercube sampling (LHS)

LHS is a statistical method for generating quasi-random parameter values from multidimensional distributions in programming that is designed to create a fair distribution between input variables to reduce the number of iterations during computational fluid dynamics (CFD) simulations. The key to the Latin hypercube method is the proper stratification of the probability distribution of the input parameters. This stratification divides the cumulative curve into equal partitions from 0 to 1.0, which is the range of the probability scale. A sample is then taken from each stratum or interval of the input distribution. The Latin hypercube sampling technique involves sampling without substitution. In a sense, the number of layers performed by the sequence is equal to the number of iterations performed on the selected sample. For example, for an input distribution with five levels, there would be five iterations. In this sampling method, another important key is to maintain independence between variables. This independence is achieved by randomly selecting input parameters in the distribution and as variables from an interval that will never be used in the future. This method avoids unnecessary correlations between parameters.

They are random sampling points on the interval [0,1]. It is obvious that for each dimension k = 1…N, only one point falls in the interval (i − 1)/N and i/N, i = 1…N. Of course, this stratification is established by superimposing layered samples on one dimension and is not expected to provide good uniformity in dimension.

The parameters in the injection molding process were considered to be coordinates in multidimensional space by the Latin hypercube sampling method. Several sampling points were selected as parameter combinations by using this sampling method, and then a mold flow simulation was performed to obtain corresponding product quality indicators, such as size, shape, and surface finish. By analyzing the experimental data, the optimal injection molding parameter combination was determined to achieve the best product quality and production efficiency. In addition, the Latin hypercube sampling method can also be used to analyze and optimize the uncertain factors in the injection molding process, such as batch differences in the raw materials, ambient temperature and other factors, thereby improving the stability and reliability of the manufacturing process. When using this method for parameter optimization, it is necessary to select the appropriate number of sampling points and distribution mode to ensure the representativeness and reliability of the obtained parameter combination. At the same time, different sampling point settings and experimental designs may be required for different injection products and requirements.

Multistrategy differential evolution algorithm (MSDE)

When the differential evolution algorithm solves complex optimization problems, it needs to consider how to ensure the global search ability and convergence of the algorithm, but the variational strategy of the classical differential evolution algorithm has obvious characteristics and shortcomings. Therefore, in this section, to improve the convergence of the algorithm and maintain the diversity of the population, three adjustment strategies are adopted, and a multistrategy differential evolution algorithm is designed by combining the elite sharing strategy, the perturbation back-solving strategy and the adaptive adjustment strategy.

Elite sharing strategy

The existing differential evolution algorithm uses the information of the current optimal individual and the possible direction of descent to design the differential mutation operator. However, this mutation operator weakens individual diversity by producing all offspring with the genetic fragments of the optimal individual. Therefore, to maintain the diversity of the population, the population is divided into several subgroups by the clustering algorithm so that the optimal individuals of the subgroups can participate in the variation process of other subgroups, thus realizing the genetic interaction among the subgroups and slowing the crisis of rapid reduction in individual genetic diversity. The specific process is as follows:

First, the k-means clustering method is used to divide the population into s subgroups, denoted as \({X}_{k}^{G}=\left\{{X}_{k1}^{G},{X}_{k2}^{G},\cdots {X}_{km}^{G}\right\}\) , where \({k}_{m}\) represents the size of the Kth subgroup k = 1,2,5. Then, the optimal individuals in each subgroup are selected to form the candidate solution set \(\left\{{X}_{b1}^{G},{X}_{b2}^{G},\cdots {X}_{bm}^{G}\right\}\) . Finally, \({X}_{bi}^{G}\) is used to generate the offspring individuals of subgroup \({X}_{j}^{G}\) , i.e.,

where \(i\ne j\) and \({X}_{kr}^{G},{X}_{ks}^{G}\in {X}_{j}^{G}\) . Notably, too small a scale to generate subpopulations using clustering may cause the above mutation operation to fail. Therefore, when the size of the subgroup is less than 3, this type of subgroup is randomly merged into other subgroups.

The K-means algorithm is a clustering analysis algorithm based on the principle of distance and proximity and is solved by multiple iterations. The main steps are as follows: First, K objects are randomly generated as the initial clustering center; second, the distance between each object and K objects is calculated, and each object is assigned to the nearest clustering center according to the distance value. Finally, the group is formed.

Perturbation reverse solution strategy

When differential evolution (DE) is used to solve complex multimodal optimization problems, it is difficult for the population to be uniformly distributed in the high-dimensional decision space, so the algorithm often stagnates due to the rapid decline in population diversity during the process of evolution. To avoid such problems, DE searches the decision space as widely as possible in the early stages of evolution to maintain population diversity. The algorithm in this section uses the reverse solution technique for poorly performing individuals rather than population initialization and therefore has a better effect on maintaining individual diversity throughout the evolutionary process. However, it should be noted that this method may have a symmetry problem due to the reverse solution, resulting in a higher gene repetition rate or similarity rate of individual offspring. To avoid the above problems, the random perturbation technique is combined with the inverse solution to perform a random perturbation on the inverse solution.

Let \(x=\left({x}_{1},{x}_{2},\cdots {x}_{D}\right)\) , where D is the dimension of the decision variable, and the reverse solution is defined as follows:

where \({x}_{j}^{U}\) and \({x}_{j}^{L}\) represent the upper and lower limits of component \({x}_{j}\) , respectively.

Notably, \({\widehat{x}}_{j}\) and \({x}_{j}\) are symmetric with respect to the center of the interval \(\left[{x}_{j}^{L},{x}_{j}^{U}\right]\) . If x is near the center point, then there may be too many redundant points in the process, which reduces the ability of the algorithm to explore new regions. To overcome this shortcoming, the following perturbation reverse solution is established as follows:

Clearly, the above equation can produce different solutions even if there are the same individuals in the population.

Adaptive adjustment strategy

The appropriate setting of parameters in the differential evolution algorithm can improve the performance of the algorithm. To obtain satisfactory algorithm performance, one of the factors to be considered is whether there is a significant difference between the fitness values of the parent individual and the offspring individual. In addition, the probability of the parent being selected as the next generation individual and the a priori success parameter values contain potentially useful information and are therefore considered in the parameter setting process of the algorithm. Based on the above considerations, a simple and effective nonparametric hypothesis test is used to propose an adaptive parameter adjustment strategy. The specific procedure is described as follows:

First,, assume we have hypothesis \({H}_{0}\) : there is no significant difference between the fitness values of the parent individual and the offspring individual. Then, we have the opposite hypothesis \({H}_{1}\) : there is a significant difference between the fitness values of the parent individual and the offspring individual.

Second, for a given significance level, the Wilcoxon signed rank test was used to test whether the original hypothesis \({H}_{0}\) was valid.

Then, the probability of the parent individual being selected as the next generation individual is calculated, denoted as p;

Finally, the Wilcoxon signed rank test results and probability value p were used to design the relevant parameter values F and CR, i.e.,

In the above equation, \(\delta \) represents the increase or decrease step size of the related parameters. Clearly, \(\delta \) should increase with decreasing evolutionary algebra, that is,

\(\delta =\frac{0.1}{{e}^{\tau \left(\frac{G}{{G}_{max}}\right)-\beta }}\)

If the original hypothesis H is rejected, then there is a significant difference between the goal value of the generation individual and the goal value of the offspring individual, and the probability value meets \(p<0.5\) . This indicates that there is a high possibility of producing high-quality offspring individuals, which means that the current parameter is valid. Therefore, the values of the variation factor F and crossover probability value CR should increase in the next generation of evolution.

If the probability value of the original hypothesis \({H}_{0}\) meets \(p>0.5\) , then there is a significant difference between the goal value of the parent individual and the goal value of the offspring individual; however, the offspring individuals produced are poor. Therefore, the values of related parameters should be reduced in the evolution process of the next generation.

If the original hypothesis \({H}_{0}\) is accepted, then the algorithm search tends to be stable, and the original parameters remain unchanged. Finally, considering the range of empirical values of parameters, if they exceed this range, then the parameter values are modified by the following rules:

In the proposed algorithm, several subpopulations are generated by the K-means clustering method. Elite individuals are selected from the subpopulation to participate in the mutation process of other subpopulations, and the elite sharing strategy is applied to produce offspring. It is expected that better individuals will be found through gene recombination so that high-quality gene fragments can be transferred to individuals in another subpopulation and interactions between genes can be realized. At the same time, the value of the variation factor F and the crossover probability CR are important factors affecting the performance of the differential evolution algorithm, and whether there is a significant difference between the individual target value of the parent and the offspring has a certain influence on the parameter setting. The Wilcoxon signed rank test with the nonparametric hypothesis can be used to assess whether there is a significant difference between the parent and offspring targets. Therefore, it is effective to use the results of the Wilcoxon signed rank test to design adaptive fitting parameters. Furthermore, the reverse perturbation strategy is applied to individuals with poor fitness in the early stage of evolution to improve the search ability of the algorithm. The differential evolution algorithm based on the reverse perturbation strategy, elite sharing strategy and adaptive adjustment strategy is referred to as SOSESDE.

The MSDE algorithm is a common optimization algorithm that searches for the best solution through a variety of different strategies. In this application, the algorithm must first define the objective function and the parameter space of the optimization problem. Then, an initial set of individuals is generated based on different strategies, and these individuals are evaluated and selected according to the objective function. Next, the individuals are updated and evolved according to the strategies using differential evolution algorithms. In each generation of evolution, the best individuals are selected, and new individuals are generated according to different strategies. This process is repeated until the stopping condition is met or the maximum evolutionary algebra is reached.

The MSDE algorithm can play an important role in the optimization of injection molding BCIs by means of the elite sharing strategy, the perturbation reverse solution strategy and the adaptive adaptation strategy. It improves the search ability and optimization effect by increasing the diversity of the search space, preserving excellent solutions, and flexibly adjusting the strategy weight.

Among them, the elite sharing strategy is a core multistrategy differential evolution algorithm. It maintains excellent individuals in the population by preserving the best solution in each generation and using it as a reference object for cross-variation by other individuals in the population. The purpose of this method is to prevent the algorithm from falling into the local optimum prematurely and to speed up the convergence to the global optimum.

In addition, the perturbation backtracking strategy is also an important part of the multistrategy differential evolution algorithm. In this strategy, the solution vector is randomly perturbed and updated toward smaller objective function values. This approach can effectively increase the exploration capacity of the search space and further improve the effect of optimization. The adaptive adjustment strategy is a key element of the multistrategy differential evolution algorithm. By adaptively adjusting the weight or probability distribution of different strategies, the algorithm can automatically adapt to different problem characteristics and optimization requirements during the search process. By dynamically adjusting the probability of using strategies, the algorithm can balance global search and local search to better cope with the complexity and diversity of problems.

Figure 5 shows a detailed map of human brain functions. The brain can be roughly divided into five functional areas, namely, the frontal lobe, parietal lobe, occipital lobe, temporal lobe and cerebellum. In this paper, the proposed BCI is mainly used to control behavior and speech. There are many nerves in the brain. When external information is transmitted, sensory neurons first receive this information and transmit it to appropriate regions in the cerebral cortex. When the information is processed and interpreted, it activates motor neurons, which trigger motor behavior. The brain controls behavior and language through coordination and communication between neurons. This control involves coordination and communication between several regions of the brain, including sensory, motor and language centers. Therefore, when designing a 3D model, we should try our best to cover each brain area with a coil circuit to improve the accuracy and reliability of information transmission.

Detailed map of brain functions.

The advantage of functional area electrode arrays is that more accurate signal separation and decoding can be achieved. By accurately recording activity in the target brain region, the accuracy and stability of the brain–computer interface (BCI) can be improved. This is important for enabling precise control and feedback of brain signals, such as motor control, speech production or external device operation. Thus, by placing electrodes according to functional areas of the brain, BCI systems can achieve greater reliability. Related studies have shown that placing electrodes in specific functional areas can improve signal specificity and selectivity, reduce interfering signals, and achieve more accurate decoding of brain signals. Based on the literature, the electrode distribution of a BCI is shown in Fig. 6 . According to the distribution of brain functional areas, corresponding electrodes are placed within each functional area. Each electrode covers the control of the whole functional area, and the control of brain activity can be analyzed and judged through the corresponding electrode output signal. It is also possible to control the corresponding brain area through external signal transmission to realize the expected commands.

Three-dimensional model of a head-mounted BCI.

In this paper, a noninvasive head-mounted brain–computer interface is designed to cover all functional regions of the brain. First, the top of the helmet is covered with a layer of 0.300 mm of electronic film using PET as the substrate, and the electrode, which is usually made of conductive metal, is designed as a microelectrode array, which is placed in accordance with the electrode positions in Fig. 6 e. This ensures that each electrode accurately captures the electrical signals of the corresponding brain region. Three-dimensional modeling is then performed to establish the structural features that conform to the human head, with the head circumference of 58 cm and the cranial top height of 10 cm, as shown in Fig. 6 a–d. The injection molding process of the BCI is simulated using Moldex3D software.

As shown in Fig. 6 e, which shows the distribution of brain electrodes according to the international standard 10–20 system, an all-inclusive brain–computer interface can provide a more comprehensive acquisition and analysis of EEG signals. The international standard 10–20 system is a commonly used electrode placement system for locating specific brain regions on the scalp. The system is based on a number of standard locations on the scalp, such as the prefrontal area (Fz), the superior area (Cz), and the occipital area (Pz), and the equidistant points between these locations 40 . With this system, using the top view shown in Fig. 5 c, the electrodes are placed at locations that correspond to specific functional areas of the brain.

Noninvasive brain–computer interfaces are technologies that enable interactions between the human brain and a computer or other devices by detecting electrical signals on the surface of the scalp. Compared with traditional invasive brain–computer interfaces, noninvasive brain–computer interfaces do not require intracranial surgery, are easy to use, are low risk, and thus have great potential for application. In this paper, PET/EVA material is used as the electronic film, LSR material is used as the injection molding material, and molten plastic is injected into the mold through high pressure to form the desired product.

In the injection molding process of the brain–computer interface, it is necessary to ensure the accuracy of the collected signals, so the quality of the film surface must be high to prevent the node displacement of the lines in the film. Therefore, in this paper, the change in node displacement on the surface of the BCI as a function of volume shrinkage is investigated, as defects due to this phenomenon can greatly affect the quality and performance of the plastic parts. In the process of injection molding, many important injection parameters are usually involved, which have a great influence on the molding quality and efficiency of the product. The melting temperature has a great influence on the fluidity and physical properties of the material, and an appropriate melting temperature can ensure the fluidity of the material to improve its ability to fill the molds and improve the dimensional accuracy of the surface of the plastic parts as well as the finish of the surface. The holding pressure will directly affect the size of the plastic parts, mainly by controlling the two aspects of molding shrinkage and deformation, so in the injection molding of the brain machine interface, reasonable holding pressure control is needed. The injection pressure determines the speed of the material entering the mold and has an effect on the filling, cooling and shrinkage of the molded parts. If the injection pressure is too high and the speed is too fast, then insufficient filling may occur. If the injection pressure is too low and the speed is too slow, then the injection cycle, as well as the molding cycle, may be prolonged.

Latin hypercube sampling is a method of designing experiments suitable for multivariate variables to better explore the relationships between variables by sampling them uniformly. In BCI manufacturing, the parameter setting of the injection material has a great influence on the performance and stability of the BCI. Therefore, the optimization of injection parameters is an important research direction, and the best combination of injection parameters can be found by exploring the relationship between injection parameters and BCI performance. The Latin hypercube sampling method can help researchers to efficiently design experiments and collect data in the case of multiple variables.

In this paper, the Latin hypercube sampling method was used to determine the sample injection molding parameters, such as the melting temperature, holding pressure, and injection pressure, while the corresponding BCI performance indicators, such as surface node displacement and volume shrinkage, were recorded. By analyzing the sampled data, the relationship between injection molding parameters and BCI performance can be obtained, and the best combination of injection molding parameters can be found.

In this experiment, Latin hypercube sampling was used to sample 20 points on the surface of the BCI, as shown in Fig. 7 . Twenty samples were randomly selected. The injection molding parameters, namely, the melting temperature (°C), pressure holding pressure (MPa) and injection pressure (MPa), were taken as experimental factors. The nodal displacement (mm) and volume shrinkage (%) of the BCI were selected as the optimization objectives. As shown in Table 2 , 20 groups of sample data were obtained via Latin hypercube sampling. Compared with the DOE experimental design method, LHS allows parameters of different dimensions to interact with each other so that the interaction relationship between parameters can be fully explored.

Latin Hypercube sampling of 20 sets of samples.

Among the 20 groups of sample data obtained by Latin hypercube sampling, the displacement and volume shrinkage of the 14th node reach a maximum of 0.792 mm and 9.566%, respectively. At this time, the node displacement will greatly affect the stability of signal transmission and reception. The displacement and volume shrinkage of the fifth node both reach a minimum of 0.470 mm and 9.533%, respectively, which is more conducive to ensuring the reliability of signal transmission and reception.

For the 23 electrode positions, considering that there are linear connections between electrodes in the membrane, in this experiment, we randomly sampled 20 points on the surface of the BCI, as shown in Figs. 8 and 9 , representing the node displacement distribution of the BCI. The bar chart shows the node displacement distribution of the entire BCI, thus more directly reflecting the performance of the system under different parameter Settings.

BCI node displacement data graph with initial parameters.

Plot of BCI volume shrinkage data with initial parameters.

As shown in Figs. 8 and 9 , the top figure represents the result value of 20 data samples obtained from Latin hypercube sampling, while the bar figure represents the distribution of node displacement and volume shrinkage respectively. We divided the change range of node displacement and volume shrinkage in the whole BCI in the process of injection molding into 10 parts and calculated their distribution proportions. The results show that the maximum distribution of node displacement is 13.67% in the range of 0.553–0.593 mm. The volume shrinkage rate is most distributed in the range of 10.149–10.580 MPa, reaching 47.10%. The experimental data show that the average coil displacement is 0.585 mm when the initial parameter holding pressure is 300 MPa, the holding time is 20 s and the melting temperature is 250 °C. The volume shrinkage was 9.992%.

BCIs often require precise electrical signal control to achieve stimulation and response of the human nervous system. Therefore, compared to the volume shrinkage rate, optimizing the node displacement can more precisely control the transmission of electrical signals and excite the target neural tissue, thus improving the functional performance of the BCI. Therefore, in this study, we optimized the coil node displacement.

Multistrategy differential evolution algorithm

BCIs have attracted much attention as direct communication channels between the human brain and external devices. These interfaces have great potential to improve the quality of life for people with movement disorders or disabilities. However, the success of BCIs depends on the precise manufacture of the interface components, in particular, the injection molding process. Injection parameters such as injection speed, temperature, pressure and mold design play a crucial role in determining the quality and function of BCIs. Therefore, the optimization of these parameters is critical. In this section, an MSDE algorithm is introduced to optimize the injection parameters of BCIs.

During each iteration, the MSDE algorithm adjusts the injection speed, temperature, pressure and mold design parameters based on the fitness evaluation of the candidate solutions. The fitness function is designed to improve the overall performance and reliability of BCIs by considering important factors such as fill quality, defect reduction and uniformity of material distribution. Figure 10 shows the flowchart of the multistrategy difference algorithm.

Multistrategy differential evolution algorithm flow block diagram.

The algorithm flow of MSDE

Define the problem Set the optimization objective of the node displacement, and consider the holding time, holding pressure and melting temperature as the optimized parameters. Additionally, set the minimization direction of the node displacement.

Initialize the population Generate the initial parameter combinations as the population, and calculate the node displacements corresponding to each parameter combination.

Elite distribution strategy Select a subset of individuals with high fitness as the elite, and share their information with the whole population. A competitive selection strategy can be used to select individuals with higher fitness as elites and crossbreed and mutate their parameter combinations with other individuals.

Perturbation reverse splicing strategy Perturbation factors are introduced to increase the search range and diversity of the algorithm. Random perturbations are introduced into the variational operation of individuals by, for example, adding random perturbations to the holding time, holding pressure and melting temperature to change the parameter values.

Adaptive adjustment strategy Adaptively adjust the parameters of the algorithm according to the current search state of the population. For example, the crossover rate and variation rate can be dynamically adjusted according to the change in population fitness to balance exploration and exploitation capabilities.

Iterative repetition The population is iteratively updated by crossover, variation and selection operations until a stopping condition is reached. The stopping condition can be when a predefined maximum number of iterations is reached or when the average or optimal fitness of the population reaches a predefined threshold. At each iteration, a selection operation is performed based on fitness, and new individuals are generated via crossover and mutation operations.

Output results The parameter combinations of the optimal individuals, i.e., the optimal holding time, holding pressure and melting temperature settings, are recorded during the iteration. These parameters are used for the injection molding process of the BCI to optimize the node displacement.

As shown in Fig. 11 , using the above multi-strategy differential evolution algorithm, the above 20 nodes can be compared with the results under the initial value, and the optimization is greater. The average node displacement of the specific BCI surface can reach 0.027 mm, which is compared with the initial node displacement of 0.585 mm, and the optimization rate is 95.38%.

Optimized node displacement distribution.

As shown in Table 3 , the optimal parameters for BCI injection molding were obtained by the multistrategy differential evolution algorithm; namely, the injection pressure was 400 MPa, the pressure holding pressure was 400 MPa, the pressure holding time was 250 s, the melting temperature was 160 °C, the mold temperature was 30 °C, and the cooling time was 30 s. The average nodal displacement of the surface reached 0.027 mm. The volume shrinkage reached 0.853%. Compared with the results before optimization, the node displacement is 0.585 mm, the volume shrinkage is 9.992%, and the optimization rates are 95.38% and 91.46%, respectively.

It can be seen from the data in the table that the optimization rate of node 14 is the highest, reaching 97.94%, and that of node 18 is the lowest, reaching 93.87%.

Results and discussion

A BCI is a technology that establishes a direct connection between the human brain and a computer or other external device to enable human‒machine interaction by interpreting EEG or other neural signals. In this study, the MSDE algorithm is used to optimize the injection parameters of the BCI. BCI technology allows neural signals to be acquired directly from the human brain and applied to control parameters in the injection molding process to improve product quality and production efficiency.

MSDE is an evolutionary algorithm-based optimization method that searches for optimal solutions in the injection molding parameter space by simulating the natural evolutionary process of variation, crossover and selection operations. The multistrategy concept allows the MSDE algorithm to use multiple evolutionary strategies simultaneously and to dynamically select the best strategy based on the characteristics of the problem. This allows the algorithm to have a better global search capability and convergence speed.

In our study, first, EVA/PET composites are selected for injection molding based on previous studies, and the geometric range of the injection parameters based on the material properties are determined. The nodal displacement of the finished product and the magnitude of volume shrinkage are obtained via mold flow simulation. Next, we use the Latin hypercube sampling method to extract 20 data points to obtain the combination of injection molding parameters corresponding to the maximum and minimum nodal displacements. Subsequently, we introduce a multistrategy differential evolution algorithm to search for the best combination of injection parameters. The algorithm evolves by generating a set of candidate solutions and using variation and crossover operations. By flexibly combining multiple strategies, the MSDE algorithm can balance exploration and exploitation in the search process, effectively finding the global optimal solution or the set of solutions close to the optimal solution. Finally, we evaluate the impact of MSDE-optimized BMI injection molding parameters on product quality and productivity through analysis and experimental validation of the optimization results. Compared with traditional manual parameter adjustment or other optimization methods, we expect to achieve better control of the injection molding process and performance improvement by combining the BCI and MSDE algorithms.

In the process of injection molding a BCI, the change in voltage difference is used to determine the amount of coil displacement, which in turn assesses the reliability of the finished BCI. BCI is a technology used to connect the human brain to external devices, allowing people to control robotic arms, prostheses or other external devices through thought control.

In an injection-molded BCI, the key components are electroencephalography (EEG) electrodes and coils. EEG electrodes are placed on the scalp to record electrical signals from the brain. These electrical signals are transmitted to an external device through the coil. While the electrical signals generated by neurons in the brain are not affected by electrode or coil displacement, the recorded signals, including neuroelectric signals, artifacts due to displacement of the electrode/tissue interface, and environmental disturbances can be affected by coil displacement. Therefore, the magnitude of coil displacement can be reflected by changes in voltage difference.

Sun et al. 17 proposed an improved eddy current sensor driving circuit. The experimental results show that the designed eddy current sensor has good linearity (1.12%) and sensitivity (2.14 V/mm), which can ensure the stable operation of the magnetic levitation turbomolecular pump at the rated speed. The relationship between the voltage change and node displacement reported in the literature is shown in Fig. 12 .

The relationship between the node displacement and voltage.

As shown in Fig. 12 , the greater the output voltage is (i.e., the measurement voltage we will eventually use), the greater the node displacement. For a 0.05 mm change in the coil displacement, the output voltage also changes by approximately 0.1 V. In this paper, we suggest that it is important to determine the magnitude of the node displacement by the magnitude of the output voltage difference to determine its compliance. By measuring the voltage difference of the coil, the node displacement can be indirectly inferred, and thus, the conformity of the product can be assessed.

According to previous research, the node displacement x and the output voltage Y is fit by the linear relationship equation Y = 1.66x + 17.54. The node displacement obtained in this paper is substituted, and the relationship graph shown in Fig. 13 is obtained. The node displacement of the optimal solution is 0.027 mm; at this time, the output voltage is 17.585 V, and the magnitude of the output voltage difference is positively correlated with the node displacement. When the node is displaced, the inductive circuit in the BCI is affected, resulting in a change in the inductance of the coil. This in turn leads to a change in the output voltage, i.e., the generation of the output voltage difference. By measuring and analyzing the output voltage difference, the magnitude of the node displacement can be determined, and the conformity of the product can be further determined.

The relationship between node displacement and output voltage.

Based on the relationship between the voltage difference and the node displacement, it can be concluded that the voltage difference of the previous injection parameters differed by approximately 11.7 V. The voltage difference of the previous injection parameters was approximately 1.5 V, which is the same as that of the node displacement. Such a large voltage difference also indicates that the node displacement of the BCI is too large. The distance between the coil and the head increases, affecting the strength and quality of the signal. As a result, the BCI may not be able to accurately detect and interpret the EEG signals, which will reduce the performance of the system. Therefore, by optimizing the injection parameters, the node displacement can reach 0.027 mm, and the voltage difference can vary by 0.054 V. The optimization rate can reach 95.38%, as shown in Fig. 14 . Smaller node displacements can improve the signal quality, positioning accuracy, stability and reliability of BCI data interpretation. Ensuring that the lines are stably fixed to the target location will help obtain high-quality and reliable EEG signals and improve the performance and functionality of the BCI.

Comparison of the voltage difference before and after optimization.

This method of determining displacement based on the output voltage difference has the advantages of accuracy and real-time performance. With proper circuit design and signal processing algorithms, the output voltage difference can be accurately measured to provide an accurate estimate of the coil displacement. Moreover, since the output voltage difference is a real-time indicator of coil displacement, the conformity of the product can be detected and determined in a timely manner to ensure the quality and reliability of the product.

In the BCI injection molding process, node displacement on the surface of the injected BMI can be significantly reduced by optimizing the dwell time, dwell pressure and melt temperature. A proper dwell time ensures that the injection plastic is fully melted and fills the mold cavity channel, avoiding defects and incomplete filling problems. Optimizing the holding pressure ensures that the injection plastic is evenly distributed and fills the mold, resulting in a flatter surface for the BCI. Optimizing the melt temperature can ensure that the injection plastic has proper flowability and plasticity, which improves the surface quality of the BMI. Therefore, the optimization of the holding time, holding pressure and melting temperature in the manufacturing process of injection-molded BCI products is crucial, and they work together to improve the product quality and ensure the reliability, accuracy and durability of the products, providing better experience and results for users.

This paper introduces the development status and trends of BCIs worldwide based on a summary of previous research and analyses and explores the injection molding process of BCIs. The main purpose of this study was to optimize the injection molding process of BCIs. First, we use the LHS method to obtain 20 sets of sample data to create a combination of injection parameters with the smallest surface node displacement and volume shrinkage rate. Second, we use the MSDE algorithm to obtain the best combination of injection molding parameters for the BCI. Finally, the node displacement can be verified by the voltage difference based on previous studies to finally determine whether the product is qualified. The main conclusions drawn from the results of the study are as follows:

There are several advantages to using IME technology to detect node displacements in BCIs. IME technology is a voltage-based measurement that evaluates the quality of a plastic part by monitoring voltage changes in the line to determine the magnitude of node displacements.

Using the LHS method, 20 sets of sample data were selected on the surface of the BCI, resulting in an average displacement of 0.585 mm and a volume shrinkage of 9.9922% for the coil under the original injection molding conditions.

The MSDE algorithm, which combines the elite sharing strategy, the perturbation inverse solution strategy and the adaptive adjustment strategy, is used to derive the parameter combination that minimizes the node displacement. When the injection pressure is 400 MPa, the holding pressure is 400 MPa, the holding time is 250 s, the melting temperature is 160 °C, the mold temperature is 30 °C and the cooling time is 30 s, the average nodal displacement of the surface can reach 0.027 mm, and the volume shrinkage can reach 0.853%. The optimization rates reached 97.94% and 93.87%, respectively.

The application of MSDE in the optimization of injection molding parameters for BCIs has the advantages of global search capability, flexibility, adaptability and low computational complexity. This makes this algorithm a powerful tool for optimizing injection molding parameters for BCIs, which effectively supports improvements in product quality, performance and productivity.

Data availability

The authors declare that the data supporting the results of this study are available in the paper. If any raw data files in other formats are required, they can be obtained from the corresponding author upon reasonable request.

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Acknowledgements

This research was funded by the 2023 Guangdong Province Science and Technology Special Fund Project—the Guangdong Taiwan Normal University Excellent Project and Technical Support by Xuying Biomedicine Co., Ltd., and Software Support by CoreTech System Co., Ltd., which are gratefully acknowledged.

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Department of Mechanical Engineering, College of Engineering, Shantou University, Shantou, 515063, China

Hanjui Chang, Yue Sun, Shuzhou Lu & Daiyao Lin

Intelligent Manufacturing Key Laboratory of Ministry of Education, Shantou University, Shantou, 515063, China

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Conceptualization, H.C.; Data curation, D.L.; Methodology, S.L.; Project administration, Y.S.; Writing—original draft, H.C. All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

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Chang, H., Sun, Y., Lu, S. et al. A multistrategy differential evolution algorithm combined with Latin hypercube sampling applied to a brain–computer interface to improve the effect of node displacement. Sci Rep 14 , 20420 (2024). https://doi.org/10.1038/s41598-024-69222-9

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Received : 08 April 2024

Accepted : 01 August 2024

Published : 03 September 2024

DOI : https://doi.org/10.1038/s41598-024-69222-9

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