Ross Vasta is Distinguished Professor of Psychology at the State University of New York at Brockport. He received his undergraduate degree from Dartmouth College in 1969 and his Ph.D. in clinical and developmental psychology from the State University of New York at Stony Brook in 1974. He is a Fellow in the American Psychological Society and the American Psychological Association (Division 7). In 1987 he was awarded the SUNY Chancellor's Award fro Excellence in Teaching. His previous books include Studying Children: An Introduction to Research Methods, Strategies and Techniques of Child Study, and Six Theories of Child Development. He is currently editor of the annual series Annals of Child Development. Marshall M. Haith is Professor of Psychology at the University of Denver. He earned his B.A. in 1959 from the University of Missouri and received his masters degree and Ph.D. from the University of California, Los Angeles, in 1964. After completing postdoctoral work at Yale University, he held positions at Harvard University, University of Geneva, and Rene Descartes University in Paris. He has been a Guggenheim Fellow and a Fellow at the Center for Advanced Study in the Behavioral Sciences. He has previously authored Day Care and Intervention Programs for Infants Under Two Years of Age and Rules That Babies Look By: The Organization of Newborn Visual Activity. Along with J.J. Campos, he edited Volume 2 of Mussen's Handbook of Child Psychology. His research interests include infant perception, the formation of expectations in early infancy, and the development of information--processing skills. Scott A. Miller is Professor of Psychology at the University of Florida. After completing his undergraduate work at Stanford University in 1996, he entered the Institute of Child Development at the University of Minnesota, where he earned his Ph.D in 1971. His initial appointment was at the University of Michigan. He is a Fellow in the American Psychological Association (Division 7). He has previously authored Developmental Research Methods, 2 nd edition, and coauthored (with John Flavell and Patricia Miller) Cognitive Development, 3 rd edition. His research has been in the cognitive area, focusing on Piaget's work, children's understanding of logical necessity, theory of mind, and parents' beliefs about children.