John M. Colford Jr. is a Professor of Epidemiology in the School of Public Health at UC Berkeley. He trained at Johns Hopkins (MD); Stanford (Chief Medical Resident); UCSF (residency in Internal Medicine and fellowships in ID and HIV/AIDS); and UC Berkeley (Epi PhD). He has served as the Principal Investigator for numerous randomized field trials and observational studies evaluating the impact of water, sanitation and hygiene interventions in India, Bolivia, Guatemala, Bangladesh, Kenya, Mexico and the United States. He teaches courses each year at UC Berkeley on Epidemiologic Methods, the Design of Randomized Controlled Trials, and on Impact Evaluation for Health Professionals. He is an attending physician in Infectious Diseases at the UCSF/VA Medical Center in San Francisco.