Marjolein Fokkema is an assistant professor in statistical methods for psychology at Leiden University. She is an expert on statistical and machine learning methods, as well as psychological assessment. She teaches bachelor and master-level courses at the Psychological and Mathematical institutes.

Her main interest is in decision-tree methods: Statistical methods that provide results in the form of decision trees. Such trees can be used to guide evidence-based decision making in clinical practice. For example, to decide which patients are at risk for developing a disorder, or which patients will benefit more from psychotherapy than medication, but the methods have a much wider range of application.

Dr. Fokkema's recent research has been published in high-impact journals such as Psychological Methods and Journal of Statistical Software (see Publications or Google Scholar). The statistical methods she develops are available in open-source software packages for the statistical programming environment R (seeĀ R packages or GitHub).