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, machine learning and psychological assessment. I teach 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 you find a short interview about my research (Dutch version here). My research 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 the methods I develop in open-source software packages for R. See link on the left for an overview. For short tutorials, or if you encountered an issue using one of my packages, head to my Github page.