2.4 Research methodology

Credibility is the trustworthiness of a qualitative account: whether its interpretation is believable given the data, method and researcher. Transferability asks whether the richly described insight can inform another context, not whether it statistically represents a population.

Transparency about sampling, procedure, analysis and limitations lets a reader judge fit. Triangulation can compare datasets or researchers, while reflexivity makes the researcher's influence visible rather than pretending interpretation is neutral.

An interview study of refugee experiences may be credible when the coding process and participant context are explicit, yet not transferable to every migration setting. The boundary is about fit and detail, not a simple pass/fail label.

Credibility is not the same as replicability, and transferability is not automatic generalisability. State which claim is being made and which evidence supports it.

Research methods are the planned ways psychologists collect and analyse evidence, such as experiments, interviews, observations, surveys and case studies. The method must operationalise the variables and fit the kind of claim being made.

Experiments can support causal inference when manipulation, comparison and control are credible. Interviews and observations can reveal meaning and behaviour in context, but researcher influence, sampling and interpretation become central validity questions.

To study whether sleep changes reaction time, an experiment can manipulate sleep opportunity and measure a defined response. To understand how students experience sleep loss, a semi-structured interview may be more informative but cannot alone establish causation.

No method is automatically superior. Identify the research question, the evidence needed, and the trade-off between control, ecological validity, ethics and transferability before judging the design.

Different methods answer different questions: experiments manipulate an independent variable for causal inference; observations record behaviour in a setting; surveys collect standardized self-report; interviews explore accounts in depth; correlational studies measure relationships without manipulation; case studies integrate multiple sources around one bounded case. Selection must fit the claim and access conditions, while ethics, demand characteristics, researcher effects, confounds and external variables limit what can be concluded.

A sample is selected from a target population so that a study can collect evidence within practical limits. Opportunity and volunteer samples are convenient; random and stratified methods aim for better representation; snowball sampling reaches hidden populations.

Choose the method from the research aim and access conditions. A random draw can still be unbalanced by chance, while a stratified design matches selected population proportions only for characteristics that were measured and used.

A study of an uncommon group may begin with one trusted participant and use referrals, gaining access but narrowing the network. A campus volunteer advert is faster but can overrepresent people who are willing and interested in the topic.

A large sample is not automatically representative. State who could be selected, who was actually selected, and how that route limits generalisation and introduces bias.