Scientific enquiry can take a number of different forms. As a result, there is 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 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.

在这里还需提请各位注意，Dr. McGowan 的母语是英语，无法阅读中文，因此请大家尽量使用英文回帖，如有任何需要与他沟通的学术和语言问题也请使用英语，Dr. McGowan 会及时回复大家的。

Dr. Daniel McGowan 曾任 Nature Reviews Neuroscience 副编辑，负责约稿，管理和撰写期刊内容。于2006年加入理文编辑（Edanz Group） 并从2008年起担任学术总监。Dr. Daniel McGowan 有超过十年的博士后和研究生阶段实验室研究经验，主要致力于神经退化疾病、分子及细胞生物学、蛋白质生物化学、蛋白质组学和基因组学。