Conduct independent analyses of WTCHR data, including employing methods designed to handle longitudinal or hierarchical data and data obtained through administrative linkages, time to event data, and methods common in epidemiology for addressing limitations of longitudinal cohort studies (e.g., missing data, attrition). To be appointed to Assignment Level II and above, candidates must have: A doctorate degree from an accredited college or university with specialization in an appropriate field of physical, biological, environmental or social science and one year of full-time experience in a responsible supervisory, administrative or research capacity in the appropriate field of specialization; or.