How to Write an Abstract: Research Papers and Dissertations

An abstract is a short, self-contained summary of a research paper, thesis or dissertation that appears before the main text. It tells readers what the study was about, how it was done, what was found and why it matters, usually in 150 to 300 words. A reader should be able to understand the essence of your work from the abstract alone, without opening the full document.

The abstract does several jobs at once:

• It helps readers decide whether to read on. Researchers scan dozens of abstracts for every paper they read in full.
• It drives discovery. Databases and search engines index abstracts, so the words you choose affect whether your work is found.
• It is used for screening. Journal editors, conference committees and systematic reviewers often make their first decision from the abstract.
• It stands in for the paper. Abstracts are often reproduced on their own in databases, conference programs and dissertation indexes.

An abstract is not an introduction. An introduction sets up the problem and leads into the paper; an abstract summarizes the whole paper, including its results and conclusions. It is also not a teaser. Withholding your findings ("results will be discussed") defeats its purpose.

Almost every abstract, in every discipline, answers four questions in order. Whether or not you use labeled headings, these are the four parts readers expect.

The proportions are a guide. The most common imbalance in student abstracts is too much background and too little about results. If your first three sentences are all context, cut them to one.

In humanities papers, the four parts take a slightly different shape: the problem or debate, your thesis, the sources and approach you use, and the contribution your interpretation makes. The logic is the same.

Write the abstract last, when your results and conclusions are final. Then follow these steps:

1. Check the requirements. Find the word limit, whether a structured format is required and whether keywords are needed. These rules come from your instructor, journal, conference or graduate school.
2. Pull one or two key sentences from each section. Reread your introduction, methods, results and discussion and highlight the sentence that best states the aim, the design, the main finding and the main conclusion.
3. Rewrite them as a single paragraph. Do not paste sentences directly; condense and connect them so the abstract reads as one coherent summary.
4. Make the results concrete. Replace "significant differences were found" with what differed, in which direction and by roughly how much.
5. Cut to the limit. Remove background beyond one sentence, method details that do not affect interpretation, and phrases such as "this paper will discuss."
6. Check it against the paper. Every claim and number in the abstract must match the main text exactly, and nothing should appear in the abstract that is not in the paper.
7. Read it as a stranger would. Would someone in your field, who has not read the paper, understand what you did and found? Define abbreviations or avoid them.

The same process applies when you write an abstract for a research project or proposal, except that you describe planned methods and expected contributions instead of results. For the full writing process, see how to write a research paper.

The length of an abstract in a research paper is almost always set by someone else, so the first rule is to follow the stated limit exactly. Typical ranges:

If no limit is given, aim for 200 to 250 words for a paper and no more than one double-spaced page for a thesis or dissertation. Writing to a tight limit is a skill: every sentence should carry information.

Abstracts come in two formats. The content is the same; the presentation differs.

Use a structured abstract only when the journal or instructor asks for one, and use exactly the headings they specify. Even in an unstructured abstract, it helps to draft with the four headings first and remove them at the end. That guarantees every part is present and in the right order.

The example below is original and describes a fictional study; all figures are invented for illustration. It is shown in unstructured form with the four parts labeled.

[Purpose] Low-stakes quizzing improves retention in laboratory studies, but its effect in large introductory courses, where students vary widely in preparation, is less clear. This study tested whether weekly online retrieval quizzes improve final exam performance in an introductory statistics course. [Methods] Six sections of the same course (N = 214 students) were randomly assigned at the section level to weekly ungraded quizzes or to weekly review readings covering the same content. Final exam scores were compared using a multilevel model accounting for section, with prior math placement scores as a covariate. [Results] Students in quiz sections scored higher on the final exam than those in reading sections (mean 74.2 percent vs. 68.9 percent; d = 0.38). The benefit was larger for students with lower placement scores, and quiz completion rates remained above 80 percent throughout the term. [Conclusion] Weekly retrieval quizzes appear to be a low-cost way to improve learning in large introductory courses, particularly for less prepared students. Because randomization occurred at the section level with only six sections, replication across more courses and institutions is needed.

Word count: about 180 words. Keywords: retrieval practice, low-stakes quizzing, statistics education, higher education.

Why it works

• Background is one sentence; the aim follows immediately.
• The methods name the design, sample, comparison and analysis without unnecessary detail.
• Results give direction and magnitude, not just "significant."
• The conclusion answers the question and notes the main limitation in one sentence.

A dissertation abstract follows the same four parts but covers a larger project, often with several studies or research questions. It should state the overall problem, summarize each major component and end with the contribution to knowledge. Does a dissertation need an abstract? Yes; virtually every graduate school requires one, and it is usually indexed separately in dissertation databases, so it must stand alone.

Example thesis abstract (original, fictional project)

[Purpose] Small-scale farmers in semi-arid regions face increasingly variable rainfall, yet the uptake of water-harvesting techniques remains uneven, and the reasons farmers adopt or abandon them are poorly understood. This dissertation examines why farmers adopt, adapt or abandon low-cost water-harvesting practices, and how local institutions shape those decisions. [Methods] Using a sequential mixed-methods design, the study combines a household survey of 412 farms in three districts with 38 in-depth interviews and observation of farmer cooperative meetings over two growing seasons. Survey data were analyzed with logistic regression; interviews were analyzed thematically. [Results] Adoption was more likely among households with secure land tenure and cooperative membership, while abandonment was associated with labor shortages rather than with doubts about effectiveness. Interviews showed that farmers frequently modified techniques to fit household labor, and that cooperatives acted as spaces for sharing these adaptations. [Conclusion] The findings suggest that extension programs focused on demonstrating technical benefits address the wrong barrier. The dissertation contributes a framework that treats adoption as an ongoing process of adaptation and recommends that programs pair technical training with labor-sharing arrangements and tenure support.

Word count: about 180 words. Many dissertation abstracts run longer, up to the institution's limit, adding a sentence per chapter or study.

Dissertation abstract template

 [1 sentence] Context and problem. [1 sentence] Aim of the dissertation / main research question. [2-3 sentences] Design, data or sources, setting, analysis. [3-4 sentences] Key findings, one per study or research question. [1-2 sentences] Conclusion and contribution to knowledge. [1 sentence] Implications for practice, policy or future research. 

Check your graduate school's formatting guide for rules on length, line spacing and whether the abstract page is numbered. For support with the wider project, see our dissertation help service.

Does a literature review need an abstract? A standalone literature review, published as a review article or submitted as an assignment, usually does. A literature review that forms a chapter or section of a larger paper or dissertation does not have its own abstract; it is covered by the abstract of the whole document.

A literature review abstract adapts the four parts:

1. Purpose: the topic, why a review is needed and the review question.
2. Methods: how sources were identified and selected, such as databases, date range and inclusion criteria. For systematic reviews this is essential; for narrative reviews, a sentence is enough.
3. Results: the main themes, patterns or areas of agreement and disagreement, and the number of sources reviewed if relevant.
4. Conclusion: the key gaps identified and what they mean for future research or practice.

Literature review abstract example (original)

Peer tutoring is widely used in higher education, but evidence on its effects is scattered across disciplines. This narrative review synthesizes research on peer tutoring in undergraduate STEM courses to identify what is known about its effects on achievement and persistence. Studies were identified through searches of education and psychology databases and screened for undergraduate STEM contexts. The review finds consistent evidence of benefits for tutors as well as tutees, weaker and more mixed evidence for effects on persistence, and limited attention to online formats. Few studies follow students beyond a single term. The review concludes that future research should examine long-term persistence and compare in-person and online tutoring models.

For guidance on the review itself, see how to write a literature review.

Tense and voice

Use the past tense for what you did and found ("Participants completed..."; "Scores increased...") and the present tense for conclusions and established knowledge ("These findings suggest..."). First person ("we surveyed") is acceptable in many fields and often clearer than passive constructions; follow your discipline's norms.

Should an abstract have citations?

Generally, no. An abstract should stand alone, and readers seeing it in a database cannot look up an in-text citation. Exceptions exist: a paper that replicates or responds directly to one specific study may name it, and some humanities journals allow a brief reference. Avoid citations unless the guidelines permit them and the reference is essential.

Other rules

• Avoid abbreviations unless they are standard in your field; define any you use.
• Do not include tables, figures or references to them.
• Do not include information that is not in the paper.
• Use the key terms a researcher would search for, especially in the first two sentences.
• If keywords are required, choose three to six terms that add to the title rather than repeat it.

The most common problems with abstracts are easy to spot once you know them:

• Too much background, leaving no room for results.
• Vague results such as "several important findings emerged."
• Promises instead of findings, such as "implications will be discussed."
• Mismatch with the paper, often because the abstract was written early and never updated.
• Exceeding the word limit, which can lead to automatic truncation in databases or rejection by submission systems.

Checklist

1. All four parts are present: purpose, methods, results, conclusion.
2. Background takes no more than one or two sentences.
3. The main results are specific, with key figures where appropriate.
4. The conclusion answers the research question.
5. Every claim and number matches the main text.
6. There are no citations, undefined abbreviations or references to figures.
7. The abstract meets the word limit and format required.

If you want an expert to check that your abstract is clear, accurate and within limits while you remain the author, our academic editing service can help.