Case study
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.
Study design
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).
