Case study methodology has a relatively long history within the sciences, social sciences, and humanities. Dating back to medical research in the early 1930s and the advent of the case history, case study research was initially viewed as useful for assisting researchers in making valid inferences from events outside the lab in ways yet consistent with the rigorous methodology of laboratory science.á As such, it gained in importance as a research strategy for identifying rich sources of data, developing into a technique that combines both qualitative and quantitative research.á Although initially rooted within a sciences approach, the case study gained even wider popularity within the social sciences and has been found to be especially valuable in such practice-oriented fields as education, management, public administration, and the human services.Despite this long history and widespread use, case study research has received perhaps the least attention among the various methodologies in the social scientist's research arsenal.á Only a few texts deal directly with it as a central subject, and no encyclopedic reference provides a thorough overview of design and methods in case study research as guidance for students, researchers, and professionals trying to incorporate case studies into a rigorous research project or program.á This work is intended to be that authoritative resource.