Welcome to my website! As you probably already noticed, my name is Marjolein Fokkema. I'm an assistant professor in statistical methods for psychology. My research focuses on statistics and machine learning, as well as psychological assessment. I teach courses at the Psychological and Mathematical institutes of Leiden University.

My main research interest is in decision-tree methods: Statistical methods that provide results in the form of decision trees. Here is a short interview about this work (Dutch version here).  

My recent work has been published in high-impact journals such as World Psychiatry, Psychological Methods, the Journal of Statistical Software and Information Fusion. For an overview, see links on the left or  my Google Scholar profile.

I implement most of my work in open-source software packages for R. For an overview, see links on the left; for short introductions and reporting issues, see my Github page.