Dr. Thomas S. Wallsten is professor emeritus in the Department of Psychology and a senior scientist with the Center for Advanced Study of Language at the University of Maryland-College Park. He received his Ph.D. from the University of Pennsylvania. Following 30 years on the faculty at the University of University of North Carolina-Chapel Hill, he moved to Maryland in 2000. He has held visiting appointments at The University of Chicago, Duke University, Haifa University in Israel, and Universität Oldenburg in Germany, the latter with the aid of a Humboldt Foundation Senior Scientist Award. A cognitive and mathematical psychologist, he has published over 100 articles and chapters primarily in the areas of probabilistic inference, judgment, choice, and communication under risk and uncertainty. He is a former editor of the Journal of Mathematical Psychology, a former associate editor of Psychometrika and of the Journal of Experimental Psychology: Learning, Memory, and Cognition and currently on the editorial board of the Psychological Review. He has served on the U.S. Environmental Protection Agency Science Advisory Board, as an associate of the National Intelligence Council, and in various advisory roles for the National Science Foundation, including a grant review panel and Committees of Visitors for two different directorates. He is an elected fellow of the Society of Experimental Psychologists and the American Psychological Association, a charter fellow of the Association for Psychological Science, a past president of the Society for Judgment and Decision Making, and a past-president of the Federation of Behavioral, Psychological, and Cognitive Sciences.