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, organization, or business. 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, 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.
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?
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 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. The use of case studies is less common today in psychology research, as most areas of psychology are dominated by quantitative research methods.
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.
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, 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. 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.