Case Study Research: Yin and Stake, Designs and Examples

Reviewed by Prof. Dr. Alexander Holtermann · Updated 16 October 2026 · 5 min read

A case study examines one or a few cases in depth and in their real-life context, using several data sources. Yin and Stake define the main approaches.

Key takeaways

A case study investigates a contemporary phenomenon in depth within its real-life context, especially when the boundary between phenomenon and context is unclear (Yin).
Yin distinguishes four designs: single or multiple cases, each holistic (one unit of analysis) or embedded (several units).
Stake distinguishes intrinsic (interest in the case itself), instrumental (the case illuminates a wider issue) and collective (several cases) case studies.
Strong case studies use multiple sources of evidence: interviews, documents, observation, archival and numerical data.
Case studies generalize analytically to theory, not statistically to populations. Define and justify your case selection clearly.

What is a case study?

A case study is a research design, not a single method. It examines one or a small number of cases in depth: an organization, a program, a school, a policy, an event, a person or a process. Robert Yin defines a case study as an empirical inquiry that investigates a contemporary phenomenon in depth and within its real-world context, particularly when the boundaries between phenomenon and context may not be clearly evident.

Case studies are well suited to “how” and “why” questions about events you cannot control. They are common in business, education, health, public policy and information systems research, and many dissertations based on a placement or a company project are case studies.

Two traditions: Yin and Stake

The two most cited authors take different positions. You do not have to choose one exclusively, but name the tradition you follow.

	Robert Yin	Robert Stake
Orientation	Systematic, design-focused, close to (post-)positivist logic	Interpretive, constructivist, focus on understanding the case
Emphasis	Protocol, propositions, rival explanations, validity tests	Particularity, holistic description, the researcher as interpreter
Typology	Single/multiple × holistic/embedded	Intrinsic, instrumental, collective
Typical use	Explanatory studies, evaluation, organizational research	Education, program evaluation, exploratory interpretive work

Yin’s four designs

Yin crosses the number of cases with the number of units of analysis.

Single-case designs are justified when the case is critical (tests a theory), extreme or unusual, common (typical), revelatory (previously inaccessible) or longitudinal.
Multiple-case designs follow replication logic: each case is like a separate experiment. Literal replication predicts similar results; theoretical replication predicts contrasting results for anticipated reasons.

	Holistic (one unit)	Embedded (several units)
Single case	Type 1: one hospital as a whole	Type 2: one hospital, analyzing three wards
Multiple cases	Type 3: four hospitals, each as a whole	Type 4: four hospitals, each with several wards

Stake’s three types

Stake classifies case studies by the purpose of studying the case:

Intrinsic: the case itself is of interest, for example a unique program you want to understand.
Instrumental: the case serves to understand a broader issue; the case is secondary.
Collective: several instrumental cases studied together to understand a phenomenon.

Planning a case study step by step

A clear plan prevents the most common problem of case studies: a lot of description, little analysis.

1. Research question: “how” or “why”, focused on a contemporary phenomenon.
2. Propositions or issues: what you expect or what you want to examine, often derived from theory.
3. Define the case and its boundaries: what exactly is the case, which time period, which people and places belong to it?
4. Case selection: justify why this case (or these cases). Use the logic of critical, typical, extreme or revelatory cases.
5. Data sources: plan at least two or three sources for triangulation.
6. Case study protocol: questions, procedures, data handling, report outline.
7. Analysis strategy: decide in advance how you will link data to propositions.

Source of evidence	Strengths	Weaknesses
Documents	Stable, exact, broad coverage	Selective, access may be restricted
Archival records	Precise, often quantitative	Privacy and access issues
Interviews	Targeted, explanatory	Bias, recall problems
Direct observation	Real time, contextual	Time-consuming, reactivity
Participant observation	Insight into behavior and motives	Researcher bias, role conflicts
Physical artifacts	Insight into practices and technology	Limited availability

Analysis strategies

Yin describes several analytic techniques that move beyond description:

Pattern matching: compare empirically observed patterns with predicted ones.
Explanation building: develop and revise an explanation of how or why something happened.
Time-series analysis: trace changes over time.
Logic models: map chains of events and outcomes.
Cross-case synthesis: compare findings across cases in a structured table.

Quality and generalization

Yin discusses four tests: construct validity (multiple sources, chain of evidence, key informants review the draft), internal validity for explanatory studies (pattern matching, rival explanations), external validity (theory in single cases, replication logic in multiple cases) and reliability (case study protocol, case study database). Interpretive case studies may instead use trustworthiness criteria.

Case studies do not generalize statistically. They generalize analytically: findings are related back to theory and can strengthen, refine or challenge it. Say this clearly in your limitations instead of apologizing for a small sample.

Tools and institutional requirements

At /codieren you can code interviews, documents and field notes from your case in one project, which makes triangulation and cross-case comparison easier. The methods tool helps you check whether a case study design fits your question. Expectations for case studies, especially company-based ones with confidentiality agreements, differ by institution; your university’s own guidelines take precedence. Upload them to Professor Digital and the plan is tailored to them.

Frequently asked questions

What is a case study in research?

A research design that examines one or a few cases, such as an organization, program or event, in depth and in their real-life context, usually with several data sources.

What is the difference between Yin and Stake?

Yin takes a systematic, design-oriented approach with propositions, protocols and validity tests. Stake takes an interpretive approach focused on understanding the particular case.

Can you generalize from a case study?

Not statistically to a population, but analytically to theory: findings can confirm, refine or challenge theoretical propositions.

How many cases should a case study have?

One case is enough if it is critical, unusual, typical, revelatory or longitudinal. Multiple-case studies often use two to four cases in a dissertation.

Is a case study qualitative or quantitative?

Mostly qualitative, but case studies can include quantitative data such as performance figures or survey results, making them mixed methods.

Sources and further reading

Yin, R. K. (2018). Case Study Research and Applications: Design and Methods (6th ed.). Sage.
Creswell, J. W., & Creswell, J. D. (2023). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches (6th ed.). Sage.

Your university’s examination regulations and style guide always take precedence.