Students learn how to be an independent investigator by developing and applying theories for understanding public health, health care services, and policy. Graduates typically are employed by universities or other organizations conducting research. This degree is offered in the Departments of Biostatistics, Environmental Sciences and Engineering, Epidemiology, Health Behavior, Health Policy and Management, Maternal and Child Health, and Nutrition. The precursor to the Ph.D. degree is typically (although not exclusively) an M.S.P.H. degree, if the research is oriented to public health, or an M.S. degree.