He holds a PhD in education sciences, an MA in sociology and an MA in education sciences from the University of Warsaw. He is a researcher in psychometrics and applied statistics in the field of education. He specializes in causal inference, multilevel analysis, structural equation modeling and IRT modeling. In addition to the methodological and statistical fields, he works on topics such as: determinants of school effectiveness, social structure, gender segregation and behavioral genetics. He has authored or co-authored several books and academic articles on these topics.