Common behavioral research methods include case studies, field experiments, observational studies, self-report inventories and surveys. The method of gathering and handling information, and the tools used to collect data, differentiate research methods from one another. Methods vary based on whether data collected is qualitative, quantitative or a combination of both.
Case studies examine one person or group's life and history extensively in an effort to discover patterns and explanations for behavior that can apply to a wider scope of people. Exploratory case studies preclude more expansive research, allowing a researcher to gather information before crafting a hypothesis or research questions. Descriptive case studies begin with a theory that is later compared against data collected. Intrinsic case studies entail the researcher having a personal involvement in the subject, and instrumental case studies involve the subject of research allowing the researcher to have access to information that is not readily obvious.
Field experiments examine people in their natural environment with variables adjusted by the researcher. While occasionally a subject is aware of the study, other times the research is covert. When a subject is not aware of the research taking place, there is less inclination for her to adjust the characteristics that may impact results. However, the researcher also relinquishes control over some extraneous components, which makes it challenging for another researcher to replicate the study.