Table of Contents
What Is an Abstract?
An abstract is a concise, self-contained summary of a research paper, thesis, dissertation, conference paper, or report. It gives readers enough information to decide whether to read the full document. Most academic abstracts run between 150 and 300 words, though some journals and programmes set tighter limits (150 words) or accept longer structured abstracts (up to 350 words).
The abstract appears at the very beginning of a document — before the introduction — but should be written last, once the paper is complete and its findings are clear.
Abstract vs Introduction
| Abstract | Introduction |
|---|---|
| Standalone — readable without the rest of the paper | Part of the paper — leads into the body |
| Includes results and conclusions | Does not reveal results |
| 150–300 words | No fixed length; often 300–800 words |
| Written last | Written early, often revised at the end |
| No citations | May include background citations |
Descriptive Abstract
A descriptive abstract describes what the paper covers without summarising the results or conclusions. It reads like an annotated table of contents. This type is now uncommon in science but still appears in some humanities and social science contexts.
Notice: no results, no conclusions — just an outline of what the paper does.
Informative Abstract
An informative abstract is the standard for most academic disciplines. It includes the problem/objective, methodology, key findings, and conclusions — everything a reader needs to understand the full scope of the research.
Objective: This study investigated the relationship between evening smartphone use and sleep quality in adults aged 18–35.
Method: A randomised crossover trial (n=142) compared sleep metrics under restricted (no screen use after 9pm) and unrestricted conditions over four weeks.
Results: Restricted screen use was associated with 23-minute longer sleep duration (p<0.01) and significantly improved sleep efficiency scores.
Conclusion: Evening screen restriction materially improves sleep quality in young adults and should be incorporated into public health guidelines.
Structured Abstract
Common in medicine, nursing, public health, and psychology, the structured abstract uses explicit section labels to organise information. Most medical journals (BMJ, JAMA, Lancet) require this format.
Standard sections vary by journal, but typically include:
- Background / Introduction — Why this question matters
- Objective / Aim — The specific research question or hypothesis
- Methods / Design — Study type, participants, interventions, measures
- Results / Findings — Key data with statistics
- Conclusions / Implications — What the findings mean for practice or policy
The 4-Sentence Formula
For non-structured informative abstracts, many academics use a four-sentence framework:
- State the problem / research gap — What is unknown or contested?
- State your approach / method — How did you investigate it?
- State your key finding — What did you discover? (the most important result)
- State the implication / conclusion — What does it mean? Why does it matter?
Conference Abstract
Conference abstracts are submitted before the paper is complete, so they often describe planned rather than completed work. They tend to be shorter (150–250 words) and emphasise novelty — why should the programme committee accept this paper?
Conference reviewers read hundreds of abstracts. Open with your key finding or the specific gap you address — not with background. The reviewer should know your contribution by the end of the first sentence.
Keywords
Most journals and many theses ask for 4–8 keywords below the abstract. These are terms used for database indexing (Google Scholar, PubMed, ERIC, PsycINFO). Good keywords:
- Include your main topic, method, population, and setting where relevant
- Mirror the terminology used in the field (check how similar papers describe themselves)
- Are specific enough to attract relevant readers but not so narrow they get zero search hits
- Avoid terms already in the title (databases already index those)
Common Mistakes
| Mistake | Fix |
|---|---|
| Writing the abstract before the paper is finished | Write last — the findings must be known |
| Including citations | Abstracts do not cite sources |
| Copying sentences verbatim from the introduction | Rewrite in condensed form — abstraction, not paste |
| Vague findings ("results showed improvement") | Include specific numbers where possible |
| Exceeding the word limit | Every journal/institution sets a limit — respect it strictly |
| Mentioning figures, tables, or section numbers | Abstracts are standalone — no internal references |
| Using abbreviations without explanation | Define all abbreviations on first use, even common ones |