A case study is an in-depth investigation of a single case or instance in a real context -- a single person, patient, group, event, community, program, organization, business, or other entity. It allows for detailed exploration of complex events or phenomena. The data involved are often gathered from observations, interviews, or other methods. Case studies have been used in clinical medicine and clinical psychology, e.g., detailed case studies of patients, focusing on a particular illness or a patient's experience. In business, one can examine a particular company's strategy and market performance. In political science and policy studies, one can investigate the complexities of a political event, campaign, or events leading to a major historical event or action (e.g., a war, a major political reform). In education, one can examine educational and learning experiences in detail from the viewpoint of student or teachers.
Case studies can focus on one individual, or a small group of individuals. It is a qualitative research method, as it does not involve a controlled comparison of carefully selected groups, and thus, is not based on the scientific method and does not involve statistical analysis. As such, it is not intended to be generalizable, i.e., for drawing general conclusions about what is true for an entire group or phenomenon, or for proving a hypothesis. Its advantage is in considering a larger number of factors that might be involved. It can be especially advantageous for exploratory study of a complex or poorly understood phenomenon, and for generating a hypothesis or model about such a phenomenon that can be followed up with other research methods. It is also ideal for more practical, non-research purposes, such as evaluating a program, or for analyzing a business to understand reasons for its success or failure.
1 Study design
Qualitative studies usually begin with a research question (unlike scientific and data-heavy quantitative research studies, which begin with a specific hypothesis that is to be proved or disproved). A research question can be more open-ended and exploratory, such as:
- Symptoms, behaviors, and possible causes of mental health issues in a psychiatric patient
- How a particular patient shows novel or interesting symptoms, and/or how the patent was treated
- How do Mexican immigrant children adapt to an English-only grade school in a small city?
- How do COVID-19 patients handle the unique psychological challenges of being quarantined at home?
- How did AMD (the CPU manufacturer) make such a strong rebound after years of poor performance?
- What are the prospects for a company's success in a new market, based on their past performance and their current business practices?
Common types of qualitative research include ethnography, content analysis, and case studies. Content analysis involves studying collections of written or oral communication, and looking for patterns or themes that emerge from the data set. This often involves identifying patterns or regularly occurring items, grouping and classifying them, and looking for themes or trends that emerge from this process. The analysis is often exploratory, but may also be guiding by an existing theoretical framework or model.
Ethnography (from the Greek 'ethnos' = people) refers to observational study of a group of people. The classic example is of an anthropologist spending an extended period of time with a tribal group or poorly understood people group, observing their behaviors, taking extensive notes, and conducting interviews with group members to understand their culture. The analysis involves inferring explanations from the data about their cultural beliefs and practices, and/or using an existing theoretical framework to explain the culture. This approach has been applied to other fields, such as educational research, e.g., where a researcher observes a classroom to study learning patterns of students, teachers' teaching methods, or the social dynamics of teachers and students. Applied linguists have used ethnography in recording conversations to analyze patterns of social interaction and language use.
A case study may simply be conducted to understand and analyze a complex situation, e.g., the growth, success, and/or failure of a company, or students' experiences in a particular learning environment. It might be used to generate a new model or hypothesis, which can lead to further research with different research methods, as in clinical case studies. It might be used for identifying anomalies that do not fit existing theories, in order to refine or challenge an existing theory (e.g., in applied linguistics research).
In clinical and educational case studies, case selection is one of the first considerations, as a study subject (the participant) must be identified who is a representative or typical sample for what one wishes to study; otherwise, if it is an atypical or outlier case, the study results will be of limited value. Sometimes this can be overcome with a larger case study of several participants, as in some educational linguistics studies.
Another consideration is the depth or "thickness" of the data, or how much detail the researcher wants to include. For example, this can range to a simple description in a few paragraphs of a language learner's experiences in a particular language course, to a very detailed biographical profile of the subject's language learning experience, his/her experiences throughout a course, multiple interviews with the subject over a semester, reports of the subject's past and current experiences and feelings, and observational data of the subject's classroom activities.
The data can be interpreted within an existing theory, model or framework for analysis, as well as the researcher's own professional experience. Additionally, interview data may be transcribed and coded (e.g., different aspects of the data are classified into different categories) and studied using other qualitative methods. The data may be analyzed without an existing theoretical framework, e.g., when a researcher conducts exploratory research on a new topic, and uses a case study as an exploratory research method to then develop a hypothesis based on the case study results. This hypothesis can then be developed and tasted in later research.
2 Use in different fields
Case studies can be used in many different fields for conducting in-depth research and finding insights into specific phenomena.
- Business and management
- Case studies are commonly used in business, especially in business schools. For example, one might study a particular company's product line, or its product development, or a particular strategy of a company. One might study a successful marketing campaign for a well-known brand, analyzing the strategies, target audience, and outcomes.
- Case studies have been famously used in psychology and psychoanalysis. Most notably, Sigmund Freud used case studies by interviewing his patients and making inferences from his interviews and observations. His case study data led to the development of his theories of psychology and psychoanalysis. Others in the Freudian framework for psychoanalysis, known as psychodynamic therapy, also used this as a primary method for research as well as for diagnosing patients. A case study might examine the effectiveness of a specific therapy approach in treating a particular psychological disorder, including assessment, intervention, and follow-up. The use of case studies is most common in clinical psychology (e.g., mental health research and counseling), and perhaps sometimes in a few other areas, such as in cross-cultural psychology and business / organizational psychology.
- Case studies are fairly common in education. For example, a case study could exploree the implementation of a new teaching methodology in a school setting, examining the impact on student learning outcomes and teacher practices. An entire school, department, or university could be examined and treated as a case, for example, to evaluate the effectiveness of an educational program, or the social dynamics among students in a school, or the effects of a particular educational policy. In second language pedagy, case studies might examine the experiences of students learning a particular skill in a foreign language, focusing on, e.g., their learning strategies, their personal struggles, their cross-cultural issues in learning the language and its culture, or how they learn a specific writing or speaking skill.
- Medicine and health care
- A case study might investigate the diagnosis and treatment of a rare or novel medical condition, including patient history, symptoms, diagnostic procedures, therapeutic interventions, and outcomes (e.g., whether the patient improved or recovered). Similarly, in the field of sports and fitness research, one might see case studies of fitness related injuries, where the diagnosis and treatment is not so obvious.
- Environmental science
- A case study might examine the effects of pollution on a specific ecosystem, analyzing the causes, consequences, and potential mitigation strategies.
- A case study can explore specific social contexts and problems. For example, one might explore the social integration of a marginalized community within a specific urban neighborhood, investigating the challenges, opportunities, and social dynamics involved.
- This might be seen in certain engineering subfields, for example, those that involve urban planning, architecture, or environmental engineering. For example, a case study might examine the design and implementation of a sustainable infrastructure project, evaluating its technical aspects, environmental impact, and cost-effectiveness.
- Law and legal studies
- Academic research in the law field can involve analyzing a landmark legal case, examining the legal arguments, judicial decisions, and implications for future legal precedents. Or a case study might examine a particular law or government regulation, how it was implemented, and its effects.
- A case study might investigate the cultural practices and social structures of a specific indigenous community, delving into their beliefs, rituals, and traditional knowledge.
- Political science
- A case study could examine a political leader's rise to power, analyzing their strategies, political campaigns, policy decisions, and the effects of the leader's policies.
2.1 Business case studies
In business fields, case studies are not usually used for exploratory purposes, or to develop new theories. They are usually used simply to describe and analyze the history of a company or organization. Many times, business case studies are less formal, as they do not rely heavily on a theory or model to explain the data, though some business case studies do make use of a model or theory that the researchers have found useful. Occasionally, case study research may be used to develop a new model for analyzing business cases. Most business case studies, however, are more semi-formal, as they are mainly used to gain a practical understanding of a company or organization. The research questions might be focused on topics such as:
- Reasons for a company's success
- Reasons for a company's poor performance
- Reasons for a company's failure
- Likely prospects for a company based on its past performance, and based on its current leadership and performance
In doing a case study, often a specific challenge or challenges are identified. The challenge may relate to the research question, or the research question might be more general. For example, a more general research question might be the future prospects of a tech company in an ever-changing tech market, and specific challenges are identified, such as possible changes in several very specific markets where the company is active.
The data in a business case study can come from a variety of sources. One might conduct interviews with company leaders, such as CEOs, executives, managers, or even lower level employees. Information may be obtained from the company website, depending on how much is published online, as well as internal documents, if one has access to company documents. This can include web pages or documents that detail company goals and vision, budgets, sales data, strategy and planning, the company's structure, and other data about the company. Survey data or interview data might be collected from employees or customers. Information may also be available from detailed news articles or analysis articles in business news magazines.
A business case study will typically lead to results such as an analysis of the company that can inform other business leaders; proposed solutions or recommendations for the company to follow; or recommendations for other companies or leaders.
Thus, a case study can contain the following components.
- Research question: The main point of the study; what the researcher wishes to find out.
- Background: A narrative of the company's growth or actions that are relevant to the study.
- Challenge: A specific challenge or challenges are identified
- Data analysis: The data are presented, interpreted, and analyzed.
- Recommendations or solutions: Based on the challenge and data, solutions or recommendations are made for what the company, or similar companies, can or should do.
- Prospects: For an existing company, its future prospects can be discussed, e.g., if it fails to adapt to challenges or implement the case study's recommendations.
These methods might also be used for case studies of other organizations, e.g., to evaluate governmental agencies, governmental organizations, non-governmental organizations (NGOs), and other entities.
Case study research in clinical psychology shows some of the limitations of this kind of research. Freud developed his psychodynamic theory of psychoanalysis and his theories of human psychology from his case study research. This, however, shows the limitations of case studies for understanding mental health issues, as many aspects of his theories were rejected by the psychological and scientific community. A case study can lead to good hypotheses and theories, or to flawed hypotheses and theories. For an important field of work that can affect people's lives, or society, a hypothesis or theory needs to be subjected to rigorous scientific testing in order to validate it. If theories are developed solely on case studies are not tested with other research methods, and are accepted simply on pragmatic grounds -- they seem to work -- this can lead to acceptance of a flawed theory. For clinical and educational fields, a flawed theory can have negative effects. For example, in Freudian theory, patients who described being victims of sexual abuse by their parents were not taken seriously; their reports were dismissed as false memories that their subconscious minds created out of latent sexual attraction to a parent. Thus, sexual abuse victims were not taken seriously. Case studies in educational and clinical research also have the drawback in that the results may not be generalizable. Again, hypotheses or claims generated by case studies generally require follow-up research with other methods to verify their claims.
However, case studies can be a valuable tool for exploratory research in different fields. In business fields, they can be a convenient method for studying companies, and can be done in a semi-formal and practical manner, so that business people and students can readily learn by studying company histories.
4 See also
- Rashid Y, Rashid A, Warraich MA, Sabir SS, Waseem A. Case Study Method: A Step-by-Step Guide for Business Researchers. International Journal of Qualitative Methods. January 2019. http://doi:10.1177/1609406919862424
- Informal case study examples (Hoffman Marketing Coummunications)
- Doing case studies
- Case study examples
- Professional sources