case-control study design A study design that entails the creation of two types of roles, such that each participant under investigation bears one or the other. What distinguishes the two types of roles is an 'outcome', which is associated with participants that have the case role but not associated with participants that have the control role. A case-control study examines the hypothesis that the presence of the outcome in case participants is associated with an 'exposure' that is not associated with control participants. John Judkins, Bjoern Peters Wikipedia, OBI case-control study design study design