1. Ming-Hui Chen is Professor, Department of Statistics, University of Connecticut, Storrs, CT 06269 . Joseph G. Ibrahim is Alumni Distinguished Professor, Department of Biostatistics, University of North Carolina, Chapel Hill, NC 27599 . Sungduk Kim is Research Fellow, Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development, NIH Rockville, MD 20852 . The authors thank the editor, the associate editor, and three referees for helpful comments...