Paul S. Levy is Senior Research Fellow at RTI International and Professor Emeritus of Epidemiology and Biostatistics in the School of Public Health at the University of Illinois. A Fellow of both the American Statistical Association and the American College of Epidemiology, Dr. Levy has authored or coauthored over 225 articles in his areas of research interest, which include sample survey methodology, design of epidemiological studies, and methodology relevant to analysis of data from observational studies.

Stanley Lemeshow, PhD, is Professor of Biostatistics and Dean of the College of Public Health at The Ohio State University. He has over thirty-five years of academic experience in the areas of regression, categorical data methods, and sampling methods. A Fellow of the American Statistical Association, Dr. Lemeshow is the coauthor of Applied Survival Analysis, Second Edition and Applied Logistic Regression, Second Edition, both published by Wiley.