2009 – Visiting Professor (Appointed), Department of Statistics, Stanford University

2006 – Professor of Applied Statistics*, Mathematical Institute, Faculty of Sciences, Leiden University

1998 – Professor of Applied Data Theory, Faculty of Social and Behavioral Sciences, Leiden University

1993 – Professor of Psychology (Adjunct), Department of Psychology, University of Illinois at Urbana-Champaign

* Since 2009 in co-operation with the Leiden-Amsterdam Center for Drug Research, Division of Analytical Biosciences and Metabolomics Center