The method section is probably the part of a psychology doctoral thesis or scientific article that causes the most headaches for students. Not because it is conceptually difficult, but because it demands a level of detail and precision that is not practiced in any other course in the degree program. While the introduction allows some room for narrative and the discussion permits cautious speculation, the method is unforgiving: every decision made during the research must be documented with sufficient clarity so that another researcher can replicate the study without needing to contact the author.
This requirement of reproducibility is what makes the method the backbone of any empirical work. A study with a brilliant introduction but a vague method is, at best, difficult to evaluate and, at worst, impossible to replicate. Thesis committees and journal reviewers know this, and that is why they tend to be especially rigorous with this section. The good news is that, once you understand the logic underlying each subsection, writing a good method becomes more of a mechanical exercise than a creative one.
Participants: more than just a number
The participants subsection must answer several fundamental questions: how many people participated, how they were selected, what their relevant demographic characteristics were, and, if there were dropouts or exclusions, how many and for what reasons. According to APA 7 standards, it is necessary to describe the sociodemographic characteristics that are relevant to the study, which varies depending on the research topic. In a study on university academic performance, age and year of study are essential. In a clinical study, the primary diagnosis, comorbidity, and current medication may be relevant.
One aspect that many students forget is justifying the sample size. It is no longer sufficient to state "120 students from University X participated." Reviewers expect to see an a priori statistical power analysis that justifies why that particular number of participants was recruited and not another. Tools such as G*Power facilitate this calculation, and mentioning it in the method demonstrates that the design was planned with rigor. It is also advisable to specify the type of sampling used (convenience, random, stratified, snowball) because this has direct implications for the generalizability of results.
When the research involves vulnerable populations or minors, it is essential to mention the informed consent procedures and the approval of the corresponding ethics committee. These details are not a bureaucratic formality but rather an indicator of the ethical quality of the study. Including the file number or reference from the ethics committee adds transparency and credibility.
If you do not have the approval yet, the ethics committee simulator anticipates the objections they usually raise: you describe the project and it returns which paragraphs are missing from the application and whether you are working with a vulnerable population without saying so. It does not replace real approval, but it saves the round of amendments that delays fieldwork by a month.
Instruments and materials
This subsection describes all the tools used to measure the study variables. For each psychometric instrument, it is necessary to indicate the full name (with the reference to the original version and the adaptation used, if applicable), the number of items, the response format (for example, a 5-point Likert scale ranging from "strongly disagree" to "strongly agree"), the dimensions or subscales that compose it, and the reliability indices obtained both in previous validation studies and in the study's own sample.
This last point is especially important and is often overlooked. Reliability is not a fixed property of an instrument but varies depending on the sample. A questionnaire may have an excellent Cronbach's alpha in the original validation sample and a mediocre one in our particular sample, which directly affects the interpretation of results. Reporting the reliability coefficients obtained in one's own sample (whether Cronbach's alpha, McDonald's omega, or the appropriate coefficient) is a practice that APA 7 standards explicitly recommend and that many thesis committees value positively.
If the study uses experimental tasks, visual stimuli, specific software for stimulus presentation (such as PsychoPy or E-Prime), or physiological recording equipment, the description must be equally detailed. Including screenshots of experimental tasks or examples of the stimuli used can be very helpful, whether in the body of the text or in an appendix.
Procedure: the chronological account
The procedure is the step-by-step narrative of what happened during data collection. It should be written in the past tense and in an order that reflects the actual temporal sequence of events. It typically begins with the initial contact with participants or the collaborating institution, continues with obtaining informed consent, proceeds with a description of the conditions under which the instruments were administered or the intervention was carried out, and ends with any debriefing or follow-up procedures.
A common error is confusing the procedure with the design. The procedure describes what was done, while the design describes the logical structure of the study (experimental, quasi-experimental, correlational, longitudinal, etc.). Some authors prefer to include a specific subsection for the design at the beginning of the method section, which helps the reader orient themselves before delving into procedural details. In any case, it is essential that the design be clearly identified, including the independent and dependent variables, the levels of each factor, and whether there was random assignment or not.
Writing this is easy when the design was well thought out and painful when it was not. If you are still in time, that is, if the method is still a plan and not an account of what you already did, paste the project into the Methodologist: it flags the design problems worth fixing, checks whether the sample size supports the model, and leaves you a draft preregistration that makes the method section almost write itself.
When the study includes an intervention or treatment, the procedure must precisely describe what each session consisted of, how many sessions there were, their duration, who delivered them, and what training that person had. If a comparison with a control group is included, it is important to specify what the control group received (waitlist, treatment as usual, active placebo) because the interpretation of results depends directly on this information.
Data analysis: methodological transparency
The final major subsection of the method describes the statistical analyses performed and the decisions that motivated them. It should include the software used (SPSS, R, JASP, Mplus, etc.) with its version number, the preliminary analyses conducted (assumption checking, treatment of outliers and missing data), and the main analyses linked to each hypothesis or research question.
The current trend across all health sciences, including nursing research, points toward greater transparency in this subsection. This means explaining not only what analyses were performed but why those were chosen over others, what criteria were used to make analytical decisions (for example, what threshold was used to identify an outlier, or what method was employed to handle missing data and why), and whether complementary robustness or sensitivity analyses were conducted. It is also increasingly common to include a reference to the study's pre-registration, if one exists, or to explicitly indicate which analyses were planned a priori and which were exploratory.
Writing a good method section requires patience and attention to detail, but the effort pays off. A well-written method not only facilitates the evaluation and replication of the study but also protects the researcher against subsequent criticism. When a reviewer asks "why did you do this that way?", the answer should already be in the method. And when someone five years from now wants to replicate or extend the study, they should be able to do so by reading only that section. That is the standard we should aspire to.