What is and what is not "traditional", will obviously depend on the historical context of a discipline, and it was already mentioned that there are different areas in which epidemiology is applied. Perhaps in Field Epidemiology we could say that the traditional study designs include cohort studies, case control studies and cross sectional studies.

From this perspective we may say that some study designs are less often used, or less 'traditional' if you like, such as Case-Case studies and Case-Cross over study designs, which are described in the following pages (click on the hyperlinks to follow).