Scientific enquiry can take a number of different forms. As a result, there are a variety of publication types, including papers describing original research, reviews, case studies, methodology papers, and theoretical papers.


By far the most common format for writing scientific papers describing original research is the IMRaD format. The letters in this acronym stand for introduction, methods, results and discussion, representing the sections lying between the abstract and references in such manuscripts (although in some journals, the methods section is presented at the end rather than after the introduction).


The International Committee of Medical Journal Editors (ICMJE), in their “Uniform Requirements for Manuscripts Submitted to Biomedical Journals: Writing and Editing for Biomedical Publication.” section IV.A.1.a (General Principles), provide the following description of the IMRaD format and why it is used:


“The text of observational and experimental articles is usually (but not necessarily) divided into the following sections: Introduction, Methods, Results, and Discussion. This so-called “IMRAD” structure is not an arbitrary publication format but rather a direct reflection of the process of scientific discovery. Long articles may need subheadings within some sections (especially Results and Discussion) to clarify their content.”

The 'write' order

The following four sections describe the important components of each of these sections as well as some common mistakes to avoid. However, it is worth mentioning that these sections should not be written in the order in which they appear (or in which they are described here). Rather, there is a specific order in which the sections of a manuscript should be written to achieve maximum clarity and consistency throughout. The recommended order for writing these sections, with the addition of the abstract and title, is as follows:

  • Methods
  • Results
  • Introduction
  • Discussion
  • Title
  • Abstract


The methods can be written while you are performing the research or, for certain standard protocols, before it has even begun. Doing this early in the course of your research could make you aware of any potential problems in your study design, or point to additional controls you might not previously have considered. The advantage of this is that the methods can be adjusted before performing experiments, preventing the need for time-consuming and costly repeats of experiments already performed.


With the methods written up and the experiments performed, you will want to analyze your results to determine how they relate to your hypothesis and what they actually show. It is pointless writing the introduction prior to this stage because the results you obtain will determine how the paper needs to be ‘framed,’ that is, what context the results are described in. Therefore, the results should be analyzed and written up second. During this stage you will determine how your data should be presented (for example, in tables, graphs, schematics or photographs; see tip on graphics), how they need to be analyzed (see tip on statistics), and what they mean. Once decided, you will then need to describe them.


By now you will have a good idea of how your findings relate to your hypothesis and the existing literature in your field. It might be necessary at this point to ask a different research question or to change the focus of your research. Following such a change, re-analyses of your data and/or additional experiments might be necessary to make a complete story. Once these are done, the introduction can be written, to provide the context, and then the discussion can be written to describe the relevance of your findings within that context. Finally, with all of that fresh in your head, the abstract and title, the important components of which are described in previous tips, should be written last.



Setting the scene


What you did


What you found


What does it all mean?