Geert Verbeke is Professor in Biostatistics at KU Leuven and Uni versiteit Hasselt in Belgium. He received the B.S. degree in mathematics (1989) from the KU Leuven, the M.S. in biostatistics (1992) from Universiteit Hasselt, and earned a Ph.D. in biostatistics (1995) from the KU Leuven. Geert Verbeke has published extensively on longitudinal data analyses. He has held visiting positions at the Gerontology Research Center and the Johns Hopkins University (Baltimore, MD). Geert Verbeke is Past President of the Belgian Region of the International Biometric Society, International Program Chair for the International Biometric Conference in Montreal (2006), Board Member of the American Statistical Association. He is past Joint Editor of the Journal of the Royal Statistical Society, Series A (2005–2008) and currently editor of Biometrics (2010– 2012). He is the director of the Leuven Center for Biostatistics and statistical Bioinformatics (L-BioStat), and vice-director of the Interuniversity Institute for Biostatistics and statistical Bioinformatics (I-BioStat), a joint initiative of the Hasselt and Leuven universities in Belgium.