Talks & Workshops


Open Science: A must for modern 21st century researchers

In this talk I will offer a gentle introduction to Open Science: What it is, how it came about, why it is needed, and what it offers.


An introduction to Bayesian statistics

This is a 2-hour workshop for the Graduate School of Medical Sciences at the UMCG, Groningen. It takes place online (and perhaps also …

Robustness of Bayesian null hypothesis testing under optional stopping

A lot has already been said against the use of optional stopping (i.e., sequential testing) in the frequentist framework. On the other …


Bayesian statistics as a therapy for frequentist problems

This workshop will highlight problems with classical inference tools ($p$-values, CIs) and provide a motivation to use Bayesian …

My current views over the Bayes factor

Null hypothesis significance testing (NHST) has been under scrutiny for decades. The literature shows overwhelming evidence of a large …

From frequentist problems towards Bayesian solutions

The social sciences are undergoing uncertain and exciting days. Perhaps unwillingly, Daryl Bem’s 2011 paper (where he incredibly makes …

Implications of teaching Bayesian statistics to undergraduate psychology students

The current crisis in psychology is claimed to be partly caused by the way we do statistics. This is one of the reasons why it has been …


Elaborating on issues with Bayes factors

Problems with frequentist statistics in general and null hypothesis significance testing in particular are a central issue in …


Three-mode principal component analysis (3MPCA) and item response theory

My talk is divided in two parts. In the first part I will offer an overview over some of my findings in three-way component analysis, …

Unfolding IRT models : Do they always fit when expected?

Item Response Theory (IRT) models are nowadays popular statistical tools in educational, psychological, and clinical assessment. …

Cumulative vs unfolding IRT models : How practice may defy theory

Item response theory (IRT) models are popular statistical tools that allow extracting psychometric information from data. These models …


Detecting misfitting response patterns in educational testing : An empirical application

Person-fit indices were applied to detect inconsistent patterns of correct/incorrect answers to test questions (items) on a high-stakes …


Detecting cheating in unproctored internet testing settings using CUSUMs (and more)

Unproctored Internet Testing (UIT) is becoming more popular in personnel recruitment and selection. A drawback of UIT is that cheating …


Simplicity transformations for three-way arrays with symmetric slices

Tucker three-way PCA and Candecomp/Parafac are two well-known methods of generalizing principal component analysis to three way data. …


Simplicity transformations for three-way arrays with symmetric slices

First and second order derivatives for CP and INDSCAL

Three-way PCA


Simplicity transformations for three-way arrays with symmetric slices


Simplicity transformations for three-way arrays with symmetric slices


A validation methodology in hierarchical clustering

This paper presents a validation methodology in ascending hierarchical clustering. The objects in validation are clustering …