I'm an assistant professor and teach at the Psychological and Mathematical Institutes of Leiden University. My research is about statistics, machine learning and psychological assessment:

I work on decision-tree methods a lot, because they are relatively easy to understand by non-statisticians. Here is a short interview about my work on trees (in Dutch).

I develop open-source software packages for the programming environment R (see left or GitHub).

My work has been published in journals like Psychological Methods, the Journal of Statistical Software, Information Fusion and World Psychiatry (see menu on the left or Google Scholar).

As Mary-Jo and the Support Vector Machines, I make music videos about statistical methods (see menu on the left or YouTube).