A good methods section is vital when writing a scientific manuscript because it provides essential information that allows the reader or reviewer to assess the validity of the results and conclusions of a study.

A very common reason for rejection on peer review is that the methods used to perform the research are not described in sufficient detail. Missing or unclear information often relates to study design, the apparatus used, and procedures followed. Thus, the rationale for the methodological choices you’ve made can appear unclear and confused.

As a general rule, methods should be sufficiently detailed to allow a competent researcher to repeat the experiments you conducted (and, hopefully, gain the same or similar results). This is how the scientific community can validate the study findings, and then continue to build on those findings to advance the field.

Unfortunately, in many cases, the methods section doesn’t allow this because it is poorly written. This could be because the author is a non-native speaker of English, but equally, researchers with proficient English language skills can often overlook the most relevant information when it comes to describing their study. This devalues the manuscript and can lead to papers being returned for revision, or worse, being rejected outright.

Both of these scenarios can be avoided by simply taking the time to ensure that you describe your methods adequately. In essence, the methods section is a “how to” guide, explaining what you did and how you did it. Not every step has to be described in detail, but the information provided should be clear enough to allow someone with research experience to repeat the experiment(s).

Firstly, your study design must be described clearly and concisely. If writing a medical report or any study observing patient groups, it’s important to include the selection criteria, sampling methods, recruitment methods, the setting, location and dates of the study, exposures or interventions and follow-up periods.

Poor description of the methods used for data is also a common fault. You must describe the variables measured and the methods and instruments used for their measurement.

When referring to the experiments themselves, it helps to ask yourself these questions:

  • Would somebody reading this description of the method be able to repeat my experiment exactly?
  • Have I described all the reagents and their concentrations?
  • Have I included the incubation times, the reaction conditions and the sources or manufacturers of the equipment and reagents used?

If the answers to these questions are yes, then you’re well on your way to writing an informative methods section.

Of course, many journals will request that well-known or “standard” methods, as well as methods that are clearly described in other publications, are simply referenced to save space. This is acceptable, but always remember to cite the relevant publications.

Finally, authors should include a section describing the methods used for data analysis, including descriptive statistics and methods for statistical inference. This section is missing in a surprising number of manuscripts, which are then inevitably returned to the author along with a request for revision.

Here, we provide only a very brief overview of the concepts that should be considered when writing the methods section of a manuscript. However, those who would like more comprehensive information may like to read the following article:

Azevedo et al., 2011: How to write a scientific paper – Writing the methods section