Melvin M. Mark is professor of psychology at the Pennsylvania State University, where he also is Head of the Department of Psychology. He has served as President of the American Evaluation Association (AEA). He was Editor of the American Journal of Evaluation (and is now Editor Emeritus). A social psychologist, Dr. Mark has wide ranging interests related to the theory, methodology and practice of evaluation, as well as a general interest in the application of social psychology to evaluation and applied social research. Dr. Mark’s awards include the American Evaluation Association’s Lazarsfeld Award for Contributions to Evaluation Theory. He is author of more than 125 articles and chapters in books. Among his books are Evaluation: An integrated framework for understanding, guiding, and improving policies and programs and the co-edited volumes Social Science and Social Policy; SAGE Handbook of Evaluation; What Counts as Credible Evidence in Applied Research and Evaluation Practice; Evaluation in Action: Interviews with Expert Evaluators; and Social Psychology and Evaluation.