KAREN GLANZ, PhD, MPH, is George A. Weiss University Professor and Director of the UPenn Prevention Research Center and the Center for Health Behavior Research at the University of Pennsylvania. BARBARA K. RIMER, DrPH, is Dean Emerita and Alumni Distinguished Professor Emerita of Health Behavior at the University of North Carolina at Chapel Hill Gillings School of Global Public Health. K. VISWANATH, PhD, is Lee Kum Kee Professor of Health Communication in the Department of Social and Behavioral Sciences at the Harvard T. H. Chan School of Public Health and Professor of Population Sciences at the Dana-Farber Cancer Institute.