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Case Study

Case Study
Also known as: Case research、Case analysis、Case investigation

A research design examining particular people, organizations or programs in depth and context. Combines sources to examine events and the validity of explanations. [1]

Case study design worksheet — openReferences and checked sections
Difficulty
Advanced
Cost
Medium
Duration
Illustrative planning durations, not common standards: design 2–4 weeks, collection per case 1–4 weeks, analysis 3–6 weeks
Content updated: 2026-10-07Source checked: 2026-09-13 (includes AI cross-checking)No documented human reviewIncludes fictional examples

How it works at a glance

Define case boundaries and selection reasons, then collect records, interviews and observations around common questions. Designs may examine one case deeply or compare different cases. [1]

Analysis goes beyond collection: develop provisional explanations, seek contrary evidence and alternatives, and revise. Do not generalize a few cases as population proportions. [1]

  1. Set research questions and design
  2. Decide case selection strategy
  3. Design collection protocols
  4. Collect multiple sources
  5. Analyze each case
  6. Cross-case analysis for multiple-case designs
  7. Present conclusions and analytical generalization
Sequence of implementation steps. See “Implementation steps” for details of each stage.

When to use it and when it is unsuitable

When to use it

  • Explain processes and contexts behind outcomes or their absence
  • Compare successful and unsuccessful implementation across areas or organizations
  • Trace complex mechanisms difficult to capture statistically
  • Document innovative or unprecedented programs in depth

When it is unsuitable

  • For large quantitative trends, surveys or existing statistics suit better
  • For statistical representativeness: case studies support analytical, not statistical generalization
  • Extremely limited time or budget: multiple-method collection needs resources

Participants, roles, and deliverables

Participants and roles

Evaluators examining cases and stakeholders. Set case numbers from questions, comparisons and resources for depth in each.

Main deliverables

  • Case study protocol
  • Case database: raw data and notes
  • Summaries for each case
  • Cross-case analysis report

Implementation steps

  1. Set research questions and design
    Select case studies for why/how questions. Define cases as individuals, organizations, projects or areas, decide single/multiple cases and design embedded units of analysis.
  2. Decide case selection strategy
    Document strategies suited to purpose: typical implementation, theoretically critical cases, deviant unexpected outcomes or maximum variation across contexts.
  3. Design collection protocols
    Specify interviews, observations, documents and archives, procedures and responsibilities in a case study protocol. Share across researchers for consistency.
  4. Collect multiple sources
    Collect interviews, observations, document reviews and other data in parallel for each case. Store systematically in a case database, separating raw data and notes.
  5. Analyze each case
    Integrate evidence into a case summary answering questions. Separate facts, interpretation and sources and record consistency and contradictions.
  6. Cross-case analysis for multiple-case designs
    Systematically compare shared patterns and differences. Use recurring patterns to support analytical generalization and consider contextual influences.
  7. Present conclusions and analytical generalization
    Compare findings with theory or propositions and cautiously present implications beyond cases. Transparently disclose selection, analysis and limitations.

Strengths and limitations

Strengths

  • Strong explanations of why and how in context
  • Describes processes, mechanisms and complex changes invisible quantitatively
  • Triangulation across sources can strengthen internal validity
  • Rich description directly supports case presentations and lessons in reports

Limitations

  • Biased selection weakens analytical generalization
  • Multiple methods and large datasets require time and skill
  • No statistical representativeness; findings may be challenged as specific to those cases
  • Prone to interpretive bias; transparent analysis matters

Common pitfalls

  • Convenience selection without reasons weakens credibility. Make strategy explicit.
  • Do not finalize explanations from one source. Plan multiple sources needed for questions and specify comparison scope and limits; documents and interviews are one possible combination.
  • Do not stop at storytelling. Structure summaries as answers with explicit evidence.

Conditions of use and evidence

  • Test provisional interpretations with additional information and examine contradictory facts. [1]
Fictional example; not actual results

Compare two organizations adopting the same training

A fictional illustration tracing plan use after training in organizations A and B.

CaseContextFictional sequence
Organization AMonthly meetingsDraft plan discussed and collection items agreed
Organization BStaff changeDraft not handed over and unused

Common errors in judgment

Common mistake

Conclude effectiveness from successes alone

How to revise

Include non-achievement cases and state selection reasons

ReasonThis examines differing success and failure conditions.

Common mistake

Report 50% success because one of two cases succeeded

How to revise

Report a comparison of two case processes

ReasonPurposive cases are not a random population sample.

Organize your thinking by writing

Case study design worksheet

A practical template is available to fill in and print on A4 paper.

Open worksheet

Related practical guides

How to conduct evaluation interviewsWhat is process evaluation?What are mixed methods?

Related methods

InterviewDocument ReviewObservationProcess TracingMost Significant Change

References and checked sections

  1. Case Study Evaluations
    U.S. General Accounting Office · 1990
    Section consulted
    Chapter 4: Data Collection and Analysis
    How it relates to the text
    Test provisional interpretations with additional information and examine contradictory facts.
    Source checked: (includes AI cross-checking)

Editorial and checking information

Content updated: Source checked: (includes AI cross-checking)No documented human reviewIncludes fictional examplesEditorial policy and scope of checkingCite this pageReport a correction

How to cite this page

EvalCompass Editorial Team. “Case Study”. EvalCompass, updated 2026-10-07. https://evalcompass.jun-nakatani.com/en/methods/case-study/
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