ERIC T. BRADLOW is associate professor of marketing and statistics at the Wharton School of the University of Pennsylvania. He also serves as associate editor for the Journal of Computational and Graphical Statistics and Psychometrika and as senior associate editor for the Journal of Educational and Behavioral Statistics. He has won numerous teaching awards and his research interests include Bayesian modeling, statistical computing, and developing new methodology for unique data structures. His current projects center on optimal resource allocation, choice modeling, and complex latent structures. He has a Ph.D. in mathematical statistics from Harvard University.

J. MICHAEL BRICK is senior statistician, vice president, and associate director of the statistical staff at Westat. He has 25 years of experience and expertise in sample design and estimation for large surveys, the theory and practice of telephone surveys, the techniques of total quality management and survey quality control, nonresponse and bias evaluation, and survey methodology. He has contributed to the statistical and substantive aspects of numerous studies and to statistical methodology research in several areas, including education, transportation, and product injury studies. He is a fellow of the American Statistical Association, an elected member of the International Statistical Institute, and a research professor in the Joint Program in Survey Methodology at the University of Maryland. He has a B.S. in mathematics from the University of Dayton and M.A. and Ph.D. degrees in statistics from American University.

EDWARD A. FRONGILLO, JR., is associate professor in the Division of Nutritional Sciences, director of the Program in International Nutrition, and director of the Office of Statistical Consulting at Cornell University. His current research activities include the Multicentre Growth Reference Study of the World Health Organization, the Food and Nutrition Technical Assistance Project of the U.S. Agency for International Development, and conceptualization and measurement of food insecurity in elders and in developing countries. He is a member of the editorial board of the Journal of Nutrition. He has an M.S. in