Appraising a Qualitative Study

A judgement of whether a qualitative study’s findings are trustworthy rather than statistically significant. The chain: a clear aim with an appropriate qualitative methodology; a fitting design and (purposive) sampling; rigorous data collection and analysis driven toward saturation with transparent coding and themes; reflexivity (the researcher’s own influence acknowledged); credibility (triangulation, member-checking); and transferability of the findings to other settings. The standard tool is the CASP qualitative checklist.

The appraisal path for work that seeks meaning, not effect size. Each step mirrors the CASP qualitative prompts: is the methodology appropriate, was sampling purposive and justified, was analysis rigorous and transparent, was the researcher’s role considered (reflexivity), and are the findings credible and transferable? The endpoint is a judgement of trustworthiness — conventionally credibility, transferability, dependability and confirmability.

Read it as a quality chain, not a statistical test. Good qualitative work uses purposive (not random) sampling to reach information-rich cases, collects data until saturation, and codes transparently so the reader can follow the route from raw data to themes. Reflexivity — the researcher naming how their own position shaped the work — is a marker examiners look for. Triangulation and member-checking support credibility; thick description supports transferability.

Qualitative research answers questions trials cannot — why patients leave the ED before being seen, how staff experience moral injury — and it is appraised on its own terms. Importing quantitative yardsticks (a power calculation, a p-value, statistical generalisability) misreads the design entirely. Recognising the right framework is the discrimination the exam tests.

• Trustworthiness = credibility · transferability · dependability · confirmability
• Purposive sampling · data to saturation · reflexivity
• Tool: CASP qualitative checklist

A qualitative study of ED experience — you appraise interviews exploring why patients leave the department before being seen, or how staff experience a major-incident debrief. Resist the urge to ask “is n = 18 enough?” Instead: was sampling purposive and the rationale stated; were data collected to saturation; is the coding transparent; did the authors show reflexivity; and are findings credible (triangulation, member-checking) and transferable? The mark goes to the candidate who appraises by trustworthiness, not by counting participants. ⚠ A missing reflexivity statement is a genuine weakness here — not a trivial omission.

• The wrong yardstick — demanding sample-size justification or p-values from qualitative work.
• Ignoring reflexivity — failing to ask how the researcher shaped the data and analysis.
• Expecting statistical generalisability rather than transferability to comparable settings.