Science Foundation-supported Active Physics Curriculum Project of the American Institute of Physics and the American Association of Physics Teachers. His many publications include a lab text on laser applications, an audiotape history of the discovery of nuclear fission, middle school and high school curriculum materials, and numerous audiovisual productions. He holds a U.S. patent for a laser vision testing system. Dr. Eisenkraft serves on several science award committees and has served as executive director for the International Physics Olympiad. He has a Ph.D. in science education from New York University and received the Presidential Award for Excellence in Science Teaching in 1986.

HERBERT P.GINSBURG is the Jacob H.Schiff foundation professor of psychology and education at Teachers College, Columbia University. His work focuses on the intellectual development and education of young children, particularly poor and minority children. He has conducted research on the development of mathematical thinking and cognition in children, examining the implications for instruction and assessment in early education. His many publications include The Development of Mathematical Thinking (1983), Piaget’s Theory of Intellectual Development (1988), Children’s Arithmetic (1989), Entering the Child’s Mind: The Clinical Interview in Psychological Research and Practice (1997), and The Teacher’s Guide to Flexible Interviewing in the Classroom (1998). Dr. Ginsburg currently serves on the National Research Council’s Committee on Early Childhood Pedagogy and on the Committee on Strategic Education Research Program Feasibility Study. He has a Ph.D. in developmental psychology from the University of North Carolina, Chapel Hill, and has taught at Cornell University, the University of Maryland, and the University of Rochester.

PAUL D.GOREN is the director of Child and Youth Development, Program on Human and Community Development, at the John D. and Catherine T. MacArthur Foundation. Previously, he was the executive director of policy and strategic services for the Minneapolis Public Schools and spent two years teaching middle school history and mathematics. He also worked as the director of the Education Policy Studies Division of the National Governors’ Association, and as the coordinator of planning and research for the Stanford Teacher Education Program. He has a Ph.D. from the Stanford University School of Education (1991) and an M.P.A. from the Lyndon B. Johnson School of Public Affairs at the University of Texas (1984).

JOSÉ P.MESTRE is a professor of physics and astronmy in the University of Massachusetts, Amherst. His research interests include cognitive studies of problem solving in physics with a focus on the acquisition and use of knowledge by experts and novices. Most recently, his work has focused on applying research findings to the design of instructional strategies that promote