Parts of a Manuscript, Headings, Subheadings, and Side Headings
A consistent pattern of organization for all headings should be used for original research articles (see also 20.1, Study Design and Statistics, The Manuscript: Presenting Study Design, Rationale, and Statistical Analysis); many scientific articles follow the IMRAD pattern (introduction, methods, results, and discussion). However, not all articles will conform to a single pattern because format and section headings vary with the type of article (see 22.0, Typography).
Introduction: The introduction should provide the context for the article, the objective of the study, and should state the hypothesis or research question (purpose statement), how and why the hypothesis was developed, and why it is important. It should convince the expert that the authors know the subject and should fill in gaps for the novice. It should generally not exceed 2 or 3 paragraphs.
Methods: The “Methods” section should include, as appropriate, a detailed description of (1) study design or type of analysis and dates and period of study, as well as mention of institutional review board or ethics committee approval (informed consent; see also 5.8, Ethical and Legal Considerations, Protecting Research Participants' and Patients' Rights in Scientific Publication); (2) condition, factors, or disease studied; (3) details of sample (eg, study participants and the setting from which they were drawn, inclusion and exclusion criteria); (4) intervention(s), if any; (5) outcome measures or observations; and (6) statistical analysis. Enough information should be provided to enable an informed reader to replicate the study, or, if a methods article has already been published, that article should be cited and important points should be summarized.
Results: The results reported in the manuscript should be specific and relevant to the research hypothesis. Characteristics of the study participants should be followed by presentation of results, from the broad to the specific. The “Results” section should not include implications or weaknesses of the study, but should include validation measures if conducted as part of the study. Results should not discuss the rationale for the statistical procedures used. Data in tables and figures should not be duplicated in the text. (See 4.0, Visual Presentation of Data.)
Discussion: The “Discussion” section should be a formal consideration and critical examination of the study. The research question or hypothesis should be addressed in this section, and the results should be compared to and contrasted with the findings of other studies. (Note: A lengthy reiteration of the results should be avoided.) The study’s limitations and the generalizability of the results should be discussed, as well as mention of unexpected findings with suggested explanations. The type of future studies needed, if appropriate, should be mentioned. This section should end with a clear, concise conclusion that does not go beyond the findings of the study. JAMA and the Archives Journals traditionally have used “Comment” rather than “Discussion” here, as the latter heading is often used for symposium proceedings or articles in which a discussion follows the presentation of a paper.