Descriptive: If the phenomenon is well established, but little is know about the internal mechanisms and causal relationships embedded in the phenomenon, your purpose may be descriptive. This approach will identify critical aspects and the boundaries of an issue or event. A case study of a successful agency delivering distance education in rural areas will tell us what makes up that agency, what roles people play, the characteristics of students, the delivery modes used, etc. From this descriptive work, ideas about relationships among the characteristics emerge, and the research design process begins again