Case StudiesPat McGee

Why Research?

● To distinguish between rival plausible hypotheses. [Campbell 1994]

● To attack proposed scientific theories. [Popper +++]

Research Tools

● Controlled experiments on population samples.● Survey● Archival Analysis● History● Case Study

Applicability of Tools [after Yin 1994]

Tool Question

Experiment How, Why Yes Present

Survey No PresentArchival (same) No BothHistory How, Why No Past

Case Study How, Why No Present

Requires Control?

Present/ Past

Who, What, Where, How

vs. Rival Theories

● Controlled experiments: requires theory to know what to control.

● Randomized experiment: Renders unstated rival theories implausible by statistics.

● Case study: Requires explicit theories in order to define models.

What is a Case Study?

● 'Case Study' is ambiguous.– Teaching case study: B-school.– Record keeping case study: medicine, law.– Research case study: many social sciences.

Research Case Study

● Purpose: distinguish between rival plausible hypotheses

● Evidence:– Documents– Artifacts– Direct observation– Interviewing– Participant observation

Yin's Definition

● “1. A case study is an empirical inquiry that● “investigates a contemporary phenomenon within

its real-life context, especially when● “the boundaries between phenomenon and

context are not clearly evident.”

Yin's Definition

● “2. The case study inquiry● “copes with the technically distinctive situation in

which there will be many more variables of interest than data points, and as one results

● “relies on multiple sources of evidence, with data needing to converge in a triangulating fashion, and as another results

● “benefits from the prior development of theoretical propositions to guide data collection and analysis.”

Parts of good case study – Yin

● Question: Why did X happen?● Propositions: X happened because of A, B, and

C.● Unit of analysis: person, team, company, etc.● Logic linking data to propositions: What effects

do data points D, E, and F have on X?● Criteria for interpreting findings: How do you

know?

Parts of a good case study – McGee

● Data

Validity

● [Copy Yin fig 2.3]

External Validity

● A case study is not a data point. Saying “you can't generalize from a single case” misses the point.

● A single case study is analogous to a single experiment. Each either supports or refutes a theory.

Types of case studies

Single-case Multiple-case

Type 1 Type 3

Type 2 Type 4

Single unit (holistic)

Multiple units (embedded)