Key Takeaways
- A case study investigates a bounded phenomenon in depth, within its real-world context, using multiple sources of evidence
- There are six main types: exploratory, descriptive, explanatory, intrinsic, instrumental, and collective: each suited to a different research purpose
- Data is collected through interviews, observations, document analysis, surveys, and physical artifacts: used in combination to triangulate findings
- Analysis moves through organization, coding, pattern identification, cross-source comparison, and theoretical interpretation
- Case studies are best suited to “how” and “why” questions; they complement rather than replace surveys, experiments, and other methods
- Rigor is achieved through construct validity, internal validity, transferability, and reliability: supported by triangulation and transparent documentation
A case study is an in-depth empirical investigation of a person, group, organization, event, or situation. It is widely used to understand a complex phenomenon in its real-world context, such as why a hospital’s infection rate dropped, how a startup scaled rapidly, or what made a school intervention succeed. This article covers everything you need to know: what a case study is, when to use one, the different types, how to conduct one step by step, and how it compares to other methods.
What Is a Case Study?
A case study is an in-depth, empirical investigation of a specific phenomenon (a person, group, organization, event, or situation) within its real-world context, using multiple sources of evidence. Rather than studying many instances at a shallow level, the case study method examines one or a small number of cases in considerable detail, capturing nuances that surveys, experiments, or large-scale quantitative studies would miss.
The key characteristics that define a case study are:
- Focus on a bounded unit: one person, one organization, one event, or one time period
- Real-world context: the phenomenon is studied as it naturally occurs, not in a laboratory
- Multiple data sources: interviews, observations, documents, and artifacts are combined
- Holistic description: the aim is to understand the whole picture, not isolate one variable
- Flexible design: methods adapt to the emerging findings throughout the study
A useful way to think about it: whereas a survey asks “how many?” and an experiment asks “does X cause Y under controlled conditions?”, a case study asks “how and why did this happen here, in this context, with these people?”
When Should You Use a Case Study?
The case study design is most appropriate in situations where context is everything and where separating a phenomenon from its environment would strip away the very meaning you are trying to understand. Specifically, use a case study when:
| Situation | Why a case study fits |
| You want to explore a new or understudied phenomenon | No established theory yet; depth over breadth needed |
| You need to explain “how” or “why” something occurred | Causal mechanisms require contextual tracing |
| Your research question begins with “how” or “why” | These are the classic triggers for case study design |
| The case is unique, rare, or extreme | Only one or very few instances exist to study |
| You want to test or refine an existing theory | A single well-chosen case can challenge or extend theory |
| You are evaluating a program or intervention | Real-world conditions matter to the assessment |
| You want to compare across contexts | Multiple cases illuminate variation and similarity |
Researchers in health sciences, education, social work, business, psychology, environmental studies, and political science all regularly use case study methodology. It is particularly valued when quantitative data alone would not capture what is most important.
Types of Case Studies
One of the most important decisions in case study research is choosing the right type of case study. Different types serve different research purposes. The most widely used classification: developed by Yin (2018) and elaborated by Stake (1995): covers the following categories.
By research purpose
Exploratory case study
An exploratory case study is conducted when little is already known about a topic. The goal is to define questions, identify variables, and develop hypotheses for future research: not to draw firm conclusions.
- Used in the early stages of inquiry
- Focuses on discovery and question generation
- Often serves as a pilot for a larger study
Example: Examining how a newly remote-first company manages team cohesion when no prior research exists on that specific organizational context.
Descriptive case study
A descriptive case study provides a complete, detailed account of a phenomenon within its context. The researcher is not trying to explain why something happened but to document what happened fully and accurately.
- Based on an established theoretical framework
- Focuses on the “what” rather than the “why”
- Produces rich, contextually detailed documentation
Example: Documenting the full process of a hospital’s transition from paper records to electronic health records, including all stakeholder responses and operational changes.
Explanatory case study
An explanatory case study aims to establish causal relationships: to explain how or why a particular outcome occurred. This is the most analytically demanding type and is frequently used in social sciences.
- Useful for causal analysis in complex real-world settings
- Seeks to identify mechanisms and processes
- Often involves theory testing
Example: Investigating why a particular school’s standardized test scores improved significantly after adopting a new pedagogical method, while neighboring schools using the same method saw no change.
By the nature of the case itself
Intrinsic case study
In an intrinsic case study, the researcher’s primary interest is in the case itself: not because it represents something broader, but because of its own inherent interest or importance.
- Driven by the unique value of the specific case
- Not designed to generalize to other contexts
- Common in biography, history, and clinical research
Example: Studying the leadership style of a particularly unconventional CEO because that individual’s approach is itself fascinating and significant.
Instrumental case study
An instrumental case study uses a specific case as a vehicle for understanding a broader issue or refining a theory. The case is secondary; the insight it enables is primary.
- The case serves as a tool for broader understanding
- Findings are intended to apply beyond the specific case
- Used for theory building and theory testing
Example: Studying one city’s response to a flooding event to understand general principles of municipal crisis management.
Collective (multiple) case study
A collective or multiple case study involves studying several cases simultaneously or sequentially to investigate a general phenomenon. The cases may be similar (replication logic) or contrasting (maximizing variation).
- Produces more robust and generalizable findings than a single case
- Cases can be analyzed individually then compared
- Stronger basis for theoretical conclusions
Example: Studying five different schools that implemented the same reading intervention to determine which contextual factors predict success or failure.
Single-case vs. multiple-case design
| Feature | Single-case design | Multiple-case design |
| Best for | Unique, critical, or revelatory cases | Theory testing, comparison, replication |
| Depth | Very high | Moderate to high |
| Generalizability | Lower | Higher |
| Resource demand | Lower | Higher |
| Example | Phineas Gage’s brain injury case in neuroscience | Comparing educational reforms across five countries |
How to Conduct a Case Study: Step-by-Step Process
Step 1: Define your research question
Everything in a case study flows from the research question. A well-formulated case study question typically:
- Begins with “how” or “why”
- Is focused enough to be answerable with one or a few cases
- Is complex enough to warrant an in-depth approach rather than a survey or experiment
Examples
Weak question: Does training improve employee performance?
Strong question: How did one manufacturing firm’s leadership development program change managerial decision-making at the team level?
Step 2: Select your case or cases
Case selection is not arbitrary. Your case should be chosen because it is particularly likely to illuminate your research question. Strategies for selection include:
| Selection strategy | When to use it |
| Typical case | To illustrate what is ordinary or common in a category |
| Extreme or deviant case | To understand what happens at the outer edges |
| Critical case | To test a theory: if it doesn’t hold here, it doesn’t hold anywhere |
| Revelatory case | To study something previously inaccessible or unexamined |
| Maximum variation | To capture the full range of diversity in a phenomenon |
Also at this stage: define the boundaries of your case clearly. What is included? What time period? Which people, locations, or events fall within the case and which fall outside it? This process is called bounding the case.
Ethical considerations must also be addressed here: informed consent, confidentiality, anonymization, and access to sensitive data.
Step 3: Build a theoretical framework
Before collecting data, situate your case study within existing theory and literature. This theoretical framework serves several purposes:
- It grounds your analysis in established knowledge
- It guides what data to collect and what to look for
- It makes your findings meaningful to your field
Conduct a focused literature review, identify the key concepts and theories relevant to your case, and decide how those theories will inform your analytical lens (whether you are testing, extending, or challenging them).
Step 4: Determine your data collection methods
Case studies are inherently multi-method. The strength of the design comes from triangulation: gathering evidence from multiple sources and checking that they converge. The main data collection methods are described below.
Interviews
Interviews are the most common data source in case study research. They can be structured, semi-structured, or unstructured depending on how much flexibility the research requires.
- Structured interviews use a fixed list of questions, making responses easy to compare
- Semi-structured interviews have a topic guide but allow follow-up and exploration
- Unstructured interviews are open-ended conversations guided by the participant
How to conduct them:
- Develop questions aligned to your research question
- Interview people with direct knowledge of the case (participants, observers, experts)
- Record and transcribe responses
- Analyze for recurring themes and patterns
Observations
Observational data is collected by the researcher directly watching and recording behavior, interactions, and events in the natural setting. Observations capture what people do, not just what they say they do.
- Participant observation: the researcher joins the activity being studied
- Non-participant observation: the researcher watches from outside without involvement
What to record: Behaviors, interactions, physical environment, sequences of events, non-verbal cues, and departures from routine.
Document analysis
Documents provide historical context, corroborate other evidence, and reveal what was formally decided or communicated. Relevant documents include:
- Reports, memos, meeting minutes, emails, policy documents
- Archival records and organizational histories
- Media coverage, published accounts, public records
How to analyze them: Identify the documents, establish their authenticity and purpose, code them systematically for relevant themes, and compare their content against interview and observation data.
Surveys
Surveys are useful for gathering structured data from a larger number of participants connected to the case. They complement qualitative findings with quantitative breadth.
- Design questions aligned to the research objectives
- Administer to participants within the case boundary
- Analyze statistically and integrate with qualitative findings
Physical artifacts
Artifacts are tangible objects related to the case: tools, products, spaces, technologies, or physical documents. They provide direct evidence that complements what people say and do.
Example: Examining a company’s actual product prototypes alongside interviews with the engineers who built them.
Step 5: Collect your data
With your protocol established, data collection should be:
- Systematic: follow your protocol consistently
- Documented: keep a case study database of all raw evidence
- Iterative: allow emerging findings to prompt new questions while staying within your research boundaries
- Ethical: maintain confidentiality and honor consent agreements throughout
Keep a research journal or reflexivity log to note your decisions, reactions, and any potential sources of bias as they arise.
Step 6: Analyze your data
Case study analysis is typically conducted through the following sequence:
| Stage | What happens |
| Organization | Sort data by source, time period, or theme; transcribe interviews |
| Coding | Assign labels to segments of data that represent concepts or themes |
| Pattern identification | Look for recurring themes, contradictions, or surprising findings across sources |
| Cross-source comparison | Check whether interview data, documents, and observations tell a consistent story |
| Theoretical interpretation | Relate your patterns to the theoretical framework established in Step 3 |
| Verification | Re-check the analysis for accuracy and consistency; seek peer review or member checking |
If you are using multiple cases, add a cross-case synthesis step: analyze each case individually first, then compare across cases to identify what varies and what is consistent.
Qualitative data analysis software can significantly assist with coding and pattern identification, particularly in complex, multi-source case studies.
Step 7: Write and report your findings
How you report a case study depends on your purpose and audience. Two broad approaches exist:
Structured (scientific paper) format:
- Introduction and research question
- Literature review and theoretical framework
- Methodology (case selection, data collection, analysis approach)
- Findings
- Discussion and implications
- Limitations
- Conclusion
Narrative format:
- Story-driven, chronological account
- Weaves data into a coherent narrative
- More common in education, social work, and humanities research
Regardless of format, your report must include:
- Background and context of the case
- A clear description of how data was collected and analyzed
- Evidence-supported findings with direct references to the data
- Discussion of how findings relate to existing theory
- Honest acknowledgment of limitations
Case Study Examples Across Disciplines
Business and management
| Element | Detail |
| Objective | Understand the growth factors behind a high-performing technology startup |
| Methods | Executive interviews, internal strategy documents, customer satisfaction surveys |
| Outcome | Identified that rapid iteration cycles and flat hierarchy: not funding level: were the primary drivers of product-market fit |
Education
| Element | Detail |
| Objective | Examine how project-based learning affects engagement among secondary school students |
| Methods | Classroom observations, teacher interviews, student performance data analysis |
| Outcome | Found significant gains in critical thinking and peer collaboration; engagement improved most in students who had previously disengaged |
Healthcare
| Element | Detail |
| Objective | Explore how a community health clinic reduced missed appointments by 40% |
| Methods | Staff interviews, patient journey mapping, appointment records analysis |
| Outcome | Identified that SMS reminders combined with flexible rescheduling: not clinical quality: drove the improvement |
Environmental science
| Element | Detail |
| Objective | Assess the impact of urban development on pollinator populations in a mid-size city |
| Methods | Wildlife field observations, environmental data analysis, interviews with urban planners |
| Outcome | Found that green corridor continuity, not green space area alone, predicted pollinator diversity |
Psychology and clinical research
| Element | Detail |
| Objective | Understand how a patient with a rare neurological condition manages daily cognitive tasks |
| Methods | Clinical interviews, cognitive assessments, behavioral observations, caregiver accounts |
| Outcome | Revealed adaptive compensatory strategies not previously documented in the literature |
Case Study vs. Other Research Methods
Choosing between methods is one of the most consequential decisions a researcher makes. The table below compares case studies to other common approaches like ethnography, surveys, and experimental research.
| Feature | Case study | Survey | Experiment | Ethnography |
| Primary question type | How, why | How many, how often | Does X cause Y? | What is it like to live/work in X? |
| Sample size | 1 to a small number | Large | Varies (often moderate) | Small, immersive |
| Depth of data | Very high | Low to moderate | Moderate | Very high |
| Generalizability | Low to moderate | High | High (if randomized) | Low |
| Control over variables | None | None | High | None |
| Best for | Complex phenomena in context | Patterns across populations | Causal claims | Cultural and social meaning |
| Time and resource demand | High | Low to moderate | Moderate to high | Very high |
The case study is not better or worse than these alternatives: it is appropriate for a different type of question. When your question requires understanding mechanisms in context rather than measuring patterns across populations, case study is the right choice.
Benefits of Case Studies
- Contextual richness: captures the complexity of real-world situations that cannot be replicated in a controlled setting
- Deep understanding: produces detailed knowledge about mechanisms, processes, and relationships within a specific case
- Methodological flexibility: can incorporate qualitative data, quantitative data, or both, adapting to the nature of the case
- Theory development: well-conducted case studies are a primary source of new theoretical propositions and conceptual frameworks
- Practical relevance: findings directly reflect real-world conditions, making them highly applicable to practitioners and policymakers
- Rare phenomena: the only viable method for studying cases that occur too infrequently to be captured by surveys or experiments
- Holistic perspective: treats the case as a whole rather than decomposing it into isolated variables
Limitations of Case Studies
| Limitation | Explanation | How to mitigate it |
| Limited generalizability | Findings from one or a few cases may not apply elsewhere | Use multiple cases; be explicit about the scope of claims |
| Researcher bias | The researcher’s perspective can shape analysis and interpretation | Use reflexivity logs, member checking, and peer review |
| Participant bias | Participants may behave differently when observed (Hawthorne effect) | Use multiple methods; compare observed behavior against self-reports |
| Time and resource intensity | In-depth data collection and analysis takes significant time | Plan carefully; scope the case boundaries tightly |
| Replication difficulty | The specific context makes exact replication nearly impossible | Document the protocol fully; be transparent about context |
| Subjectivity in analysis | Coding and interpretation involve judgment calls | Establish coding frameworks in advance; use multiple coders where possible |
Acknowledging these limitations explicitly in your report strengthens, not weakens, the credibility of your findings.
Ensuring Rigor and Quality in Case Study Research
Quality in case study research rests on four criteria, adapted from Yin (2018):
| Quality criterion | What it means | How to achieve it |
| Construct validity | You are measuring what you claim to measure | Use multiple data sources; have key informants review draft findings |
| Internal validity | Your causal conclusions are justified by the evidence | Pattern-match across sources; address rival explanations |
| External validity (transferability) | Readers can assess whether findings apply to their context | Provide thick description of the case context |
| Reliability | Another researcher following your protocol would reach similar conclusions | Document all procedures in a case study protocol |
Triangulation (the practice of cross-checking findings across different data sources, methods, or investigators) is the single most important tool for establishing rigor in case study research.
Case Studies in Medicine
Medical case studies, more precisely called case reports in clinical literature, occupy a distinct and long-established place in health research. The earliest systematic case reports date to the 19th century, and journals such as The Lancet and the New England Journal of Medicine have published them continuously since their founding. Today, dedicated journals including the BMJ Case Reports, Journal of Medical Case Reports, and SAGE Open Medical Case Reports exist solely for this form of scholarship.
A medical case study documents the clinical presentation, diagnosis, management, and outcome of an individual patient or a small group of patients. Its primary purpose is to advance clinical knowledge: alerting practitioners to rare conditions, unexpected drug interactions, novel treatment responses, or emerging disease presentations that would not appear in large-scale clinical trials because they occur too infrequently to be captured by them.
Why medicine relies on case studies
Randomized controlled trials are the gold standard for establishing treatment efficacy, but they have a structural limitation: they require sufficient patient numbers to reach statistical power, which means rare diseases, unusual presentations, and idiosyncratic drug responses are systematically excluded. Case studies fill that gap. They are particularly valuable in medicine for:
- Rare or previously undescribed conditions: documenting diseases or syndromes that affect too few patients for trial enrollment
- Unexpected drug reactions or interactions: signaling adverse effects that did not appear in pre-approval trials
- Novel treatment approaches: describing the use of an existing drug or procedure in a new clinical context
- Atypical presentations of common diseases: documenting when a well-known condition presents in an unusual way that could mislead diagnosis
- Educational purposes: training clinicians to recognize patterns across presentations they may not have personally encountered
- Hypothesis generation: providing the early signal that justifies a subsequent cohort study or trial
The COVID-19 pandemic produced hundreds of medical case reports describing atypical organ involvement, unusual coagulation effects, and rare complications in specific patient subgroups. These were observations that informed both clinical protocols and the design of subsequent trials before large-scale data were available.
How medical case studies are conducted
The conduct of a medical case study is more tightly constrained than social science case study research, governed by clinical ethics, patient confidentiality law, and journal reporting standards.
Patient selection and consent
A medical case study typically begins when a clinician encounters a patient whose presentation, response to treatment, or outcome is sufficiently unusual to warrant documentation. The patient (or guardian, if the patient is a minor or lacks capacity) must provide written informed consent before identifiable data can be reported. Most journals will not publish a case report without a signed consent statement.
Patient anonymization is standard: identifying details such as exact age, occupation, and specific location are generalized or removed unless directly clinically relevant.
Data collection
Data in a medical case study comes almost entirely from the clinical record. Sources include:
| Data source | What it contributes |
| Patient history | Symptoms, timeline, prior conditions, medications, family history |
| Physical examination findings | Objective clinical signs at presentation |
| Diagnostic investigations | Laboratory results, imaging, pathology, genetic testing |
| Clinical interventions | Treatments administered, dosages, surgical procedures |
| Outcome and follow-up | Response to treatment, recovery trajectory, complications, mortality |
| Patient-reported experience | Symptoms as described by the patient; quality-of-life impact |
Unlike social science case studies, interviews in medical case reports are primarily clinical in purpose, eliciting a symptom history, rather than exploratory or interpretive. Observation is structured through the clinical examination framework rather than ethnographic or naturalistic methods.
Literature review and contextualisation
A thorough search of the existing literature is conducted to establish whether the case has been previously reported, how common it is, and what the current clinical understanding and treatment consensus is. This contextualizes the case’s novelty and significance, and is a formal requirement of most medical journals.
How medical case studies are reported
Most medical journals require case reports to follow a standardized structure, frequently aligned with the CARE guidelines (CAse REport), a consensus-based reporting standard developed to improve completeness and transparency in clinical case reporting.
The standard sections are:
| Section | Content |
| Title | Identifies the case type; often includes the key finding or diagnosis |
| Abstract | Structured summary: introduction, patient information, diagnoses, interventions, outcomes, lessons |
| Introduction | Clinical background, why this case is notable, what it adds to existing knowledge |
| Patient information | Demographic details (anonymized), chief complaint, medical and family history |
| Clinical findings | Physical examination results |
| Timeline | Chronological table or diagram of symptoms, investigations, and interventions |
| Diagnostic assessment | Differential diagnoses considered, tests performed, final diagnosis |
| Therapeutic intervention | Treatment approach, rationale, and any modifications during the course |
| Follow-up and outcomes | Patient response, complications, adherence, and final status |
| Discussion | Interpretation of findings, comparison to existing literature, clinical implications |
| Patient perspective | Brief statement from the patient on their experience (increasingly required) |
| Informed consent statement | Confirmation that consent was obtained |
| References | Full citation list |
The CARE timeline, a structured table or visual showing dates, symptoms, investigations, and interventions in sequence, is a feature absent from social science case study reporting; it is unique to clinical case documentation. It allows clinicians to rapidly assess the pace and logic of the diagnostic and treatment process.
Key differences: medical vs. social science case studies
While both traditions share the commitment to in-depth, contextual investigation of a specific case, they differ substantially in purpose, method, reporting norms, and epistemological framing.
| Dimension | Medical case study (case report) | Social science case study |
| Primary purpose | Document a clinical event; generate diagnostic or treatment insight | Understand a social phenomenon; build or test theory |
| Unit of analysis | Almost always an individual patient | Person, group, organization, event, community, or institution |
| Data sources | Clinical records, investigations, examination findings | Interviews, observations, documents, surveys, artifacts |
| Interview role | Symptom elicitation; clinical in purpose | Exploratory, interpretive, open-ended |
| Theoretical framework | Clinical and biomedical knowledge base | Explicit social, psychological, or organizational theory |
| Analysis approach | Descriptive and comparative against literature | Thematic coding, pattern analysis, cross-case synthesis |
| Reporting standard | CARE guidelines; strict section sequence | Flexible; narrative or structured formats |
| Generalizability aim | Signal for the clinical community; hypothesis generation | Analytical generalization to theory or other contexts |
| Ethical governance | Requires written informed patient consent; IRB/ethics board review | Requires institutional ethics approval; participant consent |
| Peer review process | Clinical journal peer review; often includes statistical reviewer | Academic journal peer review; methods-focused assessment |
| Length | Typically 1,500–3,000 words | Highly variable; 5,000–15,000+ words in academic reports |
| Patient/participant voice | Brief patient perspective statement (CARE requirement) | Participant voice is often central to the analysis |
The most fundamental conceptual difference is the role of theory. Social science case studies are anchored to a theoretical framework that shapes what is collected, how it is analyzed, and what claims can be made. Medical case reports are anchored to clinical observation and biomedical context. The goal is not to build theory in the sociological sense but to document, alert, and inform clinical practice.
A second important difference is in analytical ambition. Social science case studies typically attempt to explain mechanisms, identify patterns, or extend conceptual frameworks. Medical case reports more often describe and compare: here is what happened, here is what the literature says about similar cases, here is what clinicians should watch for.
Medical case study in practice: an example
| Element | Detail |
| Case | A 34-year-old previously healthy patient presents with sudden-onset bilateral vision loss following a mild upper respiratory infection |
| Clinical finding | MRI reveals demyelinating lesions consistent with a first episode of multiple sclerosis, an atypically young presentation with an unusual trigger |
| Investigations | MRI brain and spine, lumbar puncture, visual evoked potentials, autoimmune screen |
| Intervention | High-dose intravenous corticosteroids; referral to neurology for disease-modifying therapy |
| Outcome | Partial visual recovery within six weeks; ongoing monitoring |
| Clinical contribution | Documents an atypical MS trigger and presentation pattern not well-represented in existing MS epidemiological literature; flags this presentation sequence for primary care clinicians |
Publishing medical case studies
Most clinical journals have specific submission tracks for case reports. Common requirements across journals include:
- A completed CARE checklist submitted alongside the manuscript
- Written, signed patient consent form
- Institutional ethics or IRB approval documentation (or a statement of exemption)
- Word count limits (typically 1,500–3,000 words excluding references)
- A maximum of 10–15 references
- A structured abstract of 150–250 words
- A “what this case adds to the literature” statement
Some high-impact general journals (such as the BMJ and JAMA) publish case reports selectively, favoring those with significant novelty or teaching value. Specialist case report journals accept a broader range. Researchers submitting medical case reports should consult the target journal’s author guidelines and the full CARE checklist before writing.
Frequently Asked Questions
What is a case study in research?
A case study is a research method involving in-depth, contextual investigation of a specific person, group, organization, event, or situation using multiple sources of evidence. It is used to understand complex phenomena that cannot adequately be captured through surveys or controlled experiments alone.
What are the main types of case studies?
The most widely used classification distinguishes exploratory, descriptive, and explanatory types (by research purpose) and intrinsic, instrumental, and collective types (by the nature of the case). Researchers may also design single-case or multiple-case studies depending on their objectives.
Can a case study be quantitative?
Yes. While case studies are predominantly associated with qualitative research, they can incorporate quantitative data. A mixed-methods case study might combine patient outcome statistics with clinical interview data, or use survey responses alongside ethnographic observation. What defines a case study is the in-depth, contextualized focus: not the type of data.
What makes a good case study?
A good case study has a clearly defined research question, a well-bounded and appropriately selected case, data collected from multiple sources, transparent and systematic analysis, and honest reporting of both findings and limitations. Rigor is demonstrated through triangulation, reflexivity, and thorough documentation of the research protocol.
How many cases do you need for a case study?
A case study can involve a single case or multiple cases. Single-case designs are appropriate for unique, critical, or revelatory cases. Multiple-case designs (typically 4 to 10 cases) are used when the researcher wants more robust, transferable findings or needs to compare across contexts.
What is the difference between a case study and a case report?
A case report (common in medicine) is a factual description of an individual patient’s symptoms, diagnosis, and treatment. A case study is broader and more analytical: it investigates a phenomenon systematically using a defined methodology, a theoretical framework, and multiple data sources. Case reports describe; case studies analyze.
How is a case study different from an experiment?
An experiment manipulates an independent variable under controlled conditions to establish causation. A case study observes a phenomenon as it naturally occurs, without manipulation or control. Experiments ask “does X cause Y?”; case studies ask “how and why did this outcome occur in this particular context?”
How long does a case study take?
There is no fixed duration; a focused single-case study might take a few weeks from design to write-up. A longitudinal multiple-case study examining change over time could take months or years. The timeline depends on the complexity of the case, the number of data sources, and the depth of analysis required.
How do you ensure validity in a case study?
Validity is strengthened by using multiple data sources (triangulation); having participants review draft findings (member checking); clearly documenting all methodological decisions; acknowledging rival explanations; and providing sufficiently detailed description of the case context so readers can assess transferability.
What is bounding a case in case study research?
Bounding the case means defining clearly what is and what is not part of the study: which people, events, time period, and location are included and which fall outside scope. Clear boundaries prevent scope creep during data collection and make the study coherent and defensible.
Can case studies be used to develop theory?
Yes, case studies are one of the primary routes to theory development in social science. By uncovering mechanisms and patterns not previously described, a well-conducted case study can propose new theoretical concepts or extend existing frameworks. This is distinct from theory testing, though case studies can do both.
What is the difference between an intrinsic and an instrumental case study?
An intrinsic case study focuses on a case because the case itself is interesting: the researcher wants to understand that specific person, organization, or event. An instrumental case study uses the case as a means to understand something beyond it: a broader issue, pattern, or theoretical proposition. The distinction, developed by Stake (1995), reflects whether the case is an end or a tool.
References
Creswell, J. W., & Poth, C. N. (2017). Qualitative inquiry and research design: Choosing among five approaches (4th ed.). SAGE Publications.
Stake, R. E. (1995). The art of case study research. SAGE Publications.
Yin, R. K. (2018). Case study research and applications: Design and methods (6th ed.). SAGE Publications.
This article was originally published on June 27, 2024, and updated on June 6, 2026.
