Three categories of occupations: 1.) Principal Investigator 2.) Research Scientists and Personnel 3.) Clinical Research  Management 

Research and Analysis includes jobs where practitioners extract quantitative or qualitative information from data, as well as design, supervise, and execute studies to obtain such data. Principal Investigators lead and direct studies, supervise other  personnel, and are responsible for the overall project. Research Scientists and Personnel are involved in a hands-on way by  performing specific analytical or research tasks within an organization. Clinical Research Managers aid in the organization and  regulatory aspects of clinical trials. Roles exist in many sectors including academia, government agencies, private corporations,  and public institutions