Contact information
Professional biography


Researcher at the department of Research Methodology, Measurement and Data Analysis, faculty of Behavioural, Management and Social sciences.

Development and support of multidimensional computerized adaptive testing engine (ShadowCAT), in cooperation with various external partners.

Use of video data to predict and categorize apnea events in pre-term neo-natal infants, utilizing Euclidian and phase-based motion enhancement techniques.


Researcher at Datalab, Institute for Innovation and Governance Studies, University of Twente.

Research and support for data management for faculty and staff, including the production of a booklet on data management and a templating tool for the quick creation of data management plans.

Second-line support and maintenance for the LimeSurvey survey server.


Research Master in Methodology and Statistics for the Behavioural, Biomedical and Social Sciences.

Graduated cum laude in multidimensional computerized adaptive testing.



Bachelor in European Studies.

Graduated with an average grade of 8 (out of 10).


Research interests
  • Multidimensional Computerized Adaptive Testing with Polytomous response models
    • Item selection
    • Information functions
    • Exposure control
  • Prediction of apnea events in neo-natal infants through motion magnification techiniques
    • Classification of events
    • Implementation in baby monitor app
  • Extension of IRT and CAT techniques with non-traditional types of data
    • Open text (diary entries)
    • Video (Facial expressions)
    • Audio (Dialogue)
    • Gameplay (interactions and choices in a video game)
Publications and presentations

Karel A. Kroeze, Cees A. W. Glas & Bernard P. Veldkamp (2016). Constrained Multidimensional Computerized Adaptive Testing with Polytomously scored items, submitted for publication.

Muirne C. S. Paap, Lonneke I. M. Lenferink, Nadine Herzog, Karel A. Kroeze, Job van der Palen (2016). A newly developed disease-specific item bank to measure health-related quality of life in patients with Chronic Obstructive Pulmonary Disease, submitted for publication.

Karel A. Kroeze (2015). Multidimensional computerized adaptive testing with the shadow testing procedure; implementation and challenges. RCEC Workshops, October 5-6, Enschede

Code and R packages


Allows simulation and live administration of Computer Adaptive tests. Options include; 4 models (3PLM, GPCM, GRM, SM), 3 estimators (ML, MAP, EAP), Fisher Information and Kullback-Leibler Distance based item selection, constraints, content balancing and exposure control with Shadow Testing.


MultiGHQuad: Multidimensional Gauss-Hermite Quadrature

Uses a transformed, rotated and optionally adapted n-dimensional grid of quadrature points to calculate the numerical integral of n multivariate normal distributed parameters.


Hobby projects


A JavaScript library to dynamically generate arrows with a hand drawn look and feel


RimWorld mods

Various small and some bigger mods for a game called RimWorld. C# programming, the basics of UI design, reflection and method detouring at machine code level were learned in the process.

Game Mods