Willem Sleegers

Assistant professor in social psychology


I’m an assistant professor in the Department of Social Psychology at Tilburg University. On this website you can find information about what I study, the projects I’m involved in, and blog posts about various topics related to my work. Some notable projects I’m working on are tidystats and a large-scaled replication study of cognitive dissonance.

Learn more


Latest posts


  • The right order of Method sections

    Method sections in academic (psychology) papers usually consist of the following sections: Participants, Design, Procedure, and Materials. They also tend to be presented in this order. But is this, generally speaking, the right order? I don’t think so. I think the proper order of Method sections is: Design Procedure Materials Data Analysis Participants Two things are notable here. One, there’s a Data Analysis section. Two, the Participants section is all the way at the end.

  • A tidystats example

    I illustrate how to use my tidystats software to analyze and report the results of a replication study that was part of the Many Labs 1 project.


  • Why divide by N - 1 to calculate the variance of a sample?

    In a recent tweet I asked the question why we divide by minus 1 to calculate the variance of a sample. I received many responses, but many of them were exactly of the type I feared: a statistical-jargon response that confuses me more, rather than less. Some of the responses were very useful, though, enabling me to write up this post in which I describe my favorite way of looking at this issue.

More posts


I’m an assistant professor in the Social Psychology department of Tilburg University. I have about 10 years of research experience, with publications of both scientific papers in peer-reviewed journals, as well as software publications. It should be no surprise then that my skill set consists of research skills (e.g., experimental design, data analysis, writing) and technical skills (e.g., programming).

Learn more