Mark Roberts is Associate Professor of Medicine and Chief of the Section of Decision Sciences and Clinical Systems Modeling, Division of General Medicine at the University of Pittsburgh and is, also, an Associate Professor of Health Policy and Management at the School of Public Health, and Associate Professor of Industrial Engineering at the University of Pittsburgh. He received a medical degree from Tufts University School of Medicine and the degree Master of Public Policy from the Kennedy School of Government at Harvard University. Dr. Roberts’ primary research interest is in the application of quantitative methods and decision sciences, to questions in health care, especially those that are difficult to structure in a standard randomized controlled trial format. His work has been a combination of methodology development and the application of those methods to solve real problems. He developed the use of Monte Carlo simulation methods to solve large Markov processes, and has investigated the effect of various statistical estimating techniques on the stability of the solution to decision analysis models. His current work involves the use of simulation methods in the mathematical modeling of diseases, and the use of those models to understand the optimal timing of technologic intervention in chronic disease, specifically the optimal timing of liver transplantation in end-stage liver disease. Dr. Roberts is a Fellow of the American College of Physicians.