The objective of the Methods section of an academic paper is to provide experimental or methodological details to allow other researchers to (1) evaluate the work performed, and (2) to replicate your study.
In this section you must describe exactly what you did: what, why, and how experiments were performed; and what equipment and materials were used. You should maintain a balance between conciseness and completeness: you cannot describe every technical issue, but you need to give enough detail so that your readers can interpret your results.
Giving too many details will make your paper boring and harder to read, but sub-optimal methodological details may prevent some of your readers from understanding or interpreting your results.
The most common way of organizing the Methods section of an academic paper is chronologically.
In each sub-section you need to identify the source of the samples (e.g. a specific enzyme, organism, or a culture) and of any specific type of equipment that are critical for the replication of the study. You need to describe the dates and the site where your field study was conducted, including its physical and biological characteristics of the, if that is pertinent to the study’s objectives. Describe in detail any modifications to equipment, or the nature of equipment constructed specifically for the study. If pertinent, provide illustrations.
In each sub-section you need to clearly describe the experimental design, including the hypotheses tested, the variables measured, the nature of the controls, the number of replicates, etc.
Identify treatments using the name of the variable or treatment, rather than an ambiguous, generic name or number (e.g., use "healthy donors" rather than "group 1").
The methods section has to be written in past tense. Use the active voice to explain why you had to perform a particular procedure (e.g. “In order to control for temperature, we placed the samples in…”). Use the passive voice to describe the steps of the procedure (e.g. “The samples were incubated at 37ºfor 1 h…”).
Mention the statistical tests used and the comparisons made. Common statistical methods should be used without comment, but advanced or unusual methods may require a literature citation.
Have you ever followed the instructions of a commercial assay kit? Did you find it easy to follow? That’s the balance you need to aim for!
If you are unsure whether you are providing enough detail, show your Methods section to a colleague and ask whether he or she would be able to repeat your study using only your text as a guide.
If required by the journal, mention the approval for the study by the relevant ethics committee(s) and the informed consent of the subjects.
Because different journals have different requirements for this section, you should review the journal’s guidelines before beginning to write.
A complete guided course that will teach you to efficiently write an academic paper.