Abstract: A system, a method, and a computer program product for identifying candidates for a clinical study are disclosed. A subject matter query for a study is received. Based on the received subject matter query, a group of potential candidates for participating in the study is ascertained. The subject matter query is received at a federated data repository system storing heterogeneous data. The federated data repository system translates the subject matter query and based on the translated subject matter query, the group of potential candidates is ascertained.