1. Jiahua Chen is Professor and Abbas Khalili is Postdoctoral Researcher , Department of Statistics, University of British Columbia, Vancouver, BC, Canada, V6T 1Z2. The authors thank the editor, associate editor, and referees for their insightful comments and suggestions. They also thank Bradley Efron, Department of Statistics, Stanford University, for providing the data for the HIV study in Example 1. This research was supported by the Natural Science and Engineering Research Council of Canada and by...