Dr. Mary Dupuis Sammel is Professor of Biostatistics in the Department of Biostatistics and Epidemiology and Senior Scholar in the Center for Clinical Epidemiology and Biostatistics at the Perelman School of Medicine, University of Pennsylvania in Philadelphia. She has 18 years of experience collaborating on clinical, translational, and basic research in Women's Health. Her statistical interests are in the area of observational study design as well as multivariate and longitudinal data methods. She has worked with Dr. Su since 2006.