1. Holger Dette is Professor of Mathematics (Stochastics) and Stefanie Biedermann is Assistant Professor, Department of Mathematics, Ruhr-Universität Bochum, 44780 Bochum, Germany. Wei Zhu is Associate Professor, Department of Applied Mathematics and Statistics, State University of New York, Stony Brook, NY 11794. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 475, Komplexitätsreduktion in multivariaten Datenstrukturen, Teilprojekt A2) and the National Institutes of Health (grants 3...