Case study research: what it is and how to design one

Choosing your case

Cases are chosen for their relevance to the research question, not their convenience — though access does matter practically. A 'typical' case lets you say something about ordinary practice; a 'critical' or 'extreme' case lets you test the limits of a theory; a 'revelatory' case gives access to something rarely studied.

State explicitly why this case and not another: for example, 'Organisation X was selected as a typical mid-sized manufacturer that had recently implemented the policy under study, giving access to both pre- and post-implementation staff.'

Setting the boundary

Define what is inside the case and what is context. If your case is 'the introduction of hybrid working in one NHS trust department', decide whether the boundary is the department, the trust, or the specific team affected, and over what time period.

A poorly bounded case sprawls: you end up trying to say something about the whole organisation when your data only covers one team.

Gathering multiple sources of evidence

Case study rigour comes from triangulating sources: interviews with staff, internal documents (policies, minutes, reports), and observation where access allows. Convergence across sources strengthens your claims; divergence is itself a finding worth discussing.

• Interviews or focus groups with people directly involved.
• Documentary evidence: policies, reports, minutes, communications.
• Observation of practice, where ethically and practically possible.
• Secondary data: performance figures, existing surveys, media coverage.

Analysing and writing up

Analyse within-case first — build a coherent narrative or thematic account of this case using all sources — before comparing to theory or (if you have more than one case) to other cases. Be explicit in your discussion about what is generalisable analytically (to theory) versus what is specific to this case, since statistical generalisation is not the point of case study work.

Students also ask

What is a case study in dissertation research?

A case study is an in-depth examination of a single bounded instance — an organisation, policy, event or team — studied in its real-world context using multiple sources of evidence, chosen deliberately for its relevance to the research question rather than convenience.

How do I choose which case to study?

Select a case type that matches your purpose: a typical case for ordinary practice, a critical or extreme case for testing the limits of a theory, or a revelatory case for rarely studied settings, and justify the choice explicitly in your methodology chapter.

Can case study findings be generalised?

Not statistically, but they can be generalised analytically — used to test, refine or extend a theory. Be explicit in your discussion about this distinction rather than implying your one case represents the wider population.