John Vessey, Ph.D., is a distinguished professor of Methodology and Evaluation Research at Northwestern University, having received his M.S. in Statistics from the same institution. Vessey has also earned a degree in Psychology from Wheaton College. His expertise spans across multiple fields, from epidemiology to public health. Vessey has served as Assistant Professor in both the Department of Epidemiology at the University of Minnesota School of Public Health and in the Department of Psychiatry at Northwestern University, Feinberg School of Medicine. He has also held positions of great responsibility, serving as Chief Methodologist/Evaluator for the Office of Population Affairs at the U.S. Department of Health and Human Services. Vessey is a well-respected professional in his field and continues to contribute to the advancement of knowledge in the areas of research methodology and evaluation.