How to Structure a Research Manuscript: The IMRaD Format Guide
Turning a completed study into a submission-ready manuscript means organizing it into a structure that journal editors, reviewers, and readers all expect. For most original research articles, that structure is IMRaD — Introduction, Methods, Results, and Discussion — a convention used across the sciences, health fields, and much of the social sciences since the 1970s. This guide walks through what belongs in each section, the order most experienced authors actually write them in, and how to adapt the structure to your specific target journal's requirements.
A research manuscript for journal submission typically follows the IMRaD structure: Introduction (the problem and research question), Methods (how the study was done), Results (what was found), and Discussion (what it means) — framed by a title, abstract, and references. Many authors write the sections out of reading order: Methods and Results first, Introduction last, Abstract at the very end. Exact section length and subsection requirements vary by target journal, so its author guidelines should always be checked before finalizing structure.
What Manuscript Structure Is For (and Why IMRaD)
IMRaD — Introduction, Methods, Results, and Discussion — is the standard structure for original research articles across most of the sciences, health fields, and social sciences, and is reflected in the author guidelines of journals in those fields. The structure isn't arbitrary: it mirrors the logic of the research process itself, and it lets reviewers and readers quickly locate the specific information they need — what problem was studied, how, what was found, and what it means — without reading the whole paper end to end. Reviews, case reports, theses, and some qualitative or humanities scholarship don't always follow the same shape, but IMRaD is the default for a standard original-research journal article.
The Title and Abstract
The title and abstract are what most readers, reviewers, and search engines actually see first, so both need to accurately represent the study rather than oversell it. The abstract functions as a self-contained mini-IMRaD — a short background statement, a summary of the methods, the key results, and the main conclusion — typically in the range of 150 to 300 words depending on the target journal's limit. Because it has to stand alone, the abstract shouldn't introduce any claim, number, or conclusion that isn't also supported somewhere in the body of the manuscript.
Introduction: Setting Up the Problem
A strong introduction moves from broader context to a specific, answerable research question or hypothesis, establishing why the topic matters and what gap in existing knowledge the study addresses. It should cite the literature that's directly relevant to that gap, not attempt a full literature review of the field — that level of comprehensiveness belongs in a dedicated literature review or thesis chapter, not a journal-article introduction. The introduction typically closes by stating the study's specific aim or hypothesis, so the reader knows exactly what the rest of the manuscript is going to answer.
Methods: Describing What You Did
The methods section needs enough detail that another researcher in the field could assess the study's rigor or, ideally, replicate it — covering the design, sample or materials, data-collection procedure, and analysis approach, usually as separate labeled subsections. It's typically written in the past tense, since it describes what was actually done, and organized in the same logical order the study itself followed rather than the order ideas occurred to the author. Vague methods descriptions are one of the most common reasons reviewers ask for revisions before a paper can move forward.
Results: Presenting What You Found
The results section reports findings without yet interpreting what they mean — that interpretation belongs in the discussion. Findings are usually organized in the same order as the research questions or hypotheses were introduced, so a reader can follow which result answers which question. Tables and figures are used to present data that would be tedious or hard to follow as prose, with the surrounding text highlighting the key patterns rather than restating every number the table or figure already shows.
Discussion: Interpreting Your Results
The discussion is where the results are interpreted: what they mean in relation to the research question, how they compare with existing literature, and what their broader implications are. A credible discussion also addresses the study's limitations honestly — sample size, scope, methodological constraints — rather than only presenting the findings in the most favorable light. New data or results that weren't reported in the results section shouldn't appear here for the first time; the discussion interprets what's already been presented, it doesn't introduce new findings.
Conclusion (and When It's a Separate Section)
Some journals require a distinct, short conclusion section separate from the discussion; others expect the conclusion folded into the final paragraphs of the discussion instead — checking the target journal's author guidelines settles which applies. Where a standalone conclusion is used, it's typically brief: a restatement of the main takeaway and its practical or theoretical implications, without introducing new interpretation, data, or citations that haven't already appeared in the manuscript.
The Recommended Writing Order (It's Not Introduction First)
Although IMRaD describes the order sections appear in the final manuscript, many experienced authors don't write them in that order. A common approach is to write the methods first, since the study is already complete and those details are freshest; then results, once the data and analysis are in hand; then the discussion, interpreting what the results mean; then the introduction, now that it's clear exactly what problem the paper actually answers; and the abstract last, once every other section is finished and can be accurately summarized.
How Long Should Each Section Be
Section length varies by field, journal, and article type, but a common rough guide for a 4,000–6,000 word original-research paper is: introduction around 10–15% of the total length, methods 20–25%, results 25–35%, discussion 25–35%, and a standalone conclusion (where used) around 5%. These are proportions, not fixed rules — a methods-heavy clinical trial and a discussion-heavy exploratory study will reasonably differ from this split, and the target journal's own word limits and section requirements always take precedence.
Matching Structure to Your Target Journal's Requirements
Journals and fields deviate from a strict IMRaD template in real, specific ways: some require a combined “Results and Discussion” section, some mandate a standalone “Limitations” subsection, some cap word counts per section rather than for the whole manuscript, and many humanities and certain qualitative-research journals don't use IMRaD at all. Checking the target journal's author guidelines before finalizing structure — ideally before writing begins, not after a full draft is finished — avoids a restructuring pass late in the process.
Common Mistakes in Manuscript Structure
The most frequent structural problems are: blending results and interpretation together instead of keeping them in separate sections; introducing new results for the first time in the discussion; writing an introduction that reads like a full literature review instead of focusing on the specific gap the study addresses; a methods section too thin for another researcher to assess or replicate; and an abstract that doesn't actually match the claims made in the body of the manuscript.
When to Get Support Structuring or Writing Your Manuscript
Structuring a manuscript from a completed study, a thesis or dissertation chapter, or a set of results and notes is often where authors get stuck — particularly first-time authors, non-native English speakers, or anyone assembling a stand-alone journal article out of a larger project. Getting an experienced outside read on structure and language before submission, rather than after a rejection or major-revision request, is generally the more efficient path, especially when the target journal's specific formatting expectations still need to be matched.
Frequently asked questions
IMRaD stands for Introduction, Methods, Results, and Discussion — the standard four-part structure used by most original-research journal articles, framed by a title, abstract, and reference list.
No. IMRaD is the default for original-research articles across most of the sciences, health fields, and social sciences, but review articles, case reports, and much humanities and qualitative scholarship use different structures — always check your target journal's author guidelines.
Many experienced authors write Methods first, then Results, then Discussion, then the Introduction, and finally the Abstract — the reverse of the order readers encounter them in.
It varies by journal and field, but a common rough split for a 4,000–6,000 word paper is Introduction 10–15%, Methods 20–25%, Results 25–35%, Discussion 25–35%, and Conclusion around 5%. Always check your target journal's specific word limits.
The Discussion interprets your results, compares them with existing literature, and addresses limitations. The Conclusion, when a journal requires it as a separate section, is a short restatement of the main takeaway and its implications, without introducing new interpretation.
References
- PMC (National Library of Medicine) — How to Write a Successful Research Manuscript: Back to Basics
A peer-reviewed overview of the manuscript-writing and IMRaD-structuring process for research articles.
- Editage Insights — Tips for Writing the Perfect IMRAD Manuscript
Practical guidance on structuring each IMRaD section of a research manuscript.
- American Medical Writers Association — IMRAD Format Explained
An explanation of the IMRaD format and how it structures a scientific manuscript for clarity.
- CASRAI — Manuscript Writing: A Practical Guide
A practical guide to the research-manuscript writing and structuring process.