About the Author: PAUL P. BIEMER, PhD, is Chief Scientist at the Research Triangle Institute in North Carolina. ROBERT M. GROVES, PhD, is Program Director (Senior Research Scientist) in the Survey Research Center of the University of Michigan, where he also serves as Director in the Institute for Social Research and Professor of Sociology. LARS E. LYBERG, PhD, is Chief Scientist at Statistics Sweden in Stockholm. NANCY A. MATHIOWETZ, PhD, is Special Assistant Director for Statistical Design, Methodology, and Standards at the U.S. Bureau of the Census. SEYMOUR SUDMAN, PhD, is the Walter A. Stellner Professor of Marketing and Deputy Director of the Survey Research Laboratory at the University of Illinois, Urbana-Champaign.