Leiden University, Department of Psychology, M&T, PO Box 9555, 2300 RB Leiden, The Netherlands

Recently I received the VIDI scholarshp from NWO. To see more details about the planned research see an interview with the Leiden University Newsletter (in Dutch / English) 

I study the way people change. When change is measured on an interval variable (for example body length) people always make little steps on this scale from small to large. Statistical methods for analyzing such data take this scale into account. However, when categorical data is measured such a scale or in multidimensional terms 'map' is never (i.e. in no statistical model) taken into account, although the same reasoning is valid that people make little steps. To understand change in a categorical variable, it is necessary to recover the map from the data. This is done by distance association models (De Rooij and Heiser, 2005).  

To deal with measurements at three time points triadic distance models were developed and studied in a number of papers (De Rooij and Heiser, 2000; De Rooij, 2002; Gower and De Rooij, 2003; and De Rooij and Gower, 2003). These triadic distance models were incorporated in the distance association framework lately (De Rooij, submitted paper).

• Docent van master course Interaction Models.
• Docent van de 2e jaars cursus MVDA (Met Kees van Putten, Peter de Heus, en Kees Verduin) (2000-2006)
• Docent van master course Optimization (2005-2006)
• Docent Psychometrie (2003)

Current projects

1. De Rooij, M. Ideal point discriminant analysis revisited. Manuscript submitted.
2. De Rooij, M. Trend vector models for multiple groups in continuous time.
3. Polak, M.G., Heiser, W.J. & De Rooij, M. Item analysis of unipolar item response data.
4. Wit, A. & De Rooij, M.. Social value orientations and parochial cooperation.
5. Busing, F.M.T.A. & De Rooij, M. Incomplete multidimensional unfolding. Manuscript submitted.
6. Gower, J.C. & De Rooij, M.. Model terms in Biometrics and Psychometrics.
7. Merens, W., Van der Does, A.J.W., De Rooij, M. Van Vliet, I. & Veen, G. Cognitive effects after initiating SSRI-treatment in depressed patients..

Main Publications 

These papers are copyright: Pdf-versions are made available for personal study only, and must not be re-distributed!

1. De Rooij, M.. The analysis of change, Newton's law of gravity, and Association models. Journal of the Royal Statistical Society, series A. Accepted paper.
2. De Kwaatsteniet, Wit, Van Dijk, De Cremer and De Rooij. Justifying Decisions in Social Dilemmas:Justification Pressures and Tacit Coordination under Environmental uncertainty. Personality and Social Psychology Bulletin. Accepted Paper
3. De Rooij, M. & Anderson, C.J. Visualising, Summarizing and Comparing odds ratio structures. Methodology. Accepted paper. Manuscript. Matlab program
4. De Rooij, M. (2007). The distance perspective of generalized biadditive models: scalings and transformations. Journal of Computational and Graphical Statistics, 16, 210-227. This article may be downloaded for personal use only.
5. De Rooij, M.. The use of covariates in distance association models for the analysis of change. In: Van Montfort, K., Oud, H., and Sattora, A. (Eds) "Longitudinal models in the behavioral and related sciences", (pp, 367-380). Mahwah, New Jersey: Lawrence Erlbaum Associates.
6. De Rooij, M. and Heiser, W.J. (2005). Graphical Representations and Odds Ratios in a Distance Association Model for the Analysis of Cross Classified Data, Psychometrika, 70, 99-122. This article may be downloaded for personal use only.
7. De Rooij, M. and Kroonenberg, P.M. (2003). Multivariate multinomial logit models for dyadic sequential interaction data, Multivariate Behavioral Research, 38, 463-504. This article may be downloaded for personal use only.
8. De Rooij, M. and Gower, J.C. (2003). The geometry of triadic distances, Journal of Classification, 20, 181-220.
9. De Rooij, M. (2003). Statistical Modeling using Euclidean distances. Bulletin of the International Statistical Institute, 54^th session. Proceedings. August, 2003. Berlin, Germany.
10. Gower, J.C. and De Rooij, M. (2003). A comparison of the multidimensional scaling of triadic and dyadic distances, Journal of Classification, 20, 115-136.This article may be downloaded for personal use only.
11. De Rooij, M. and Heiser, W.J. (2003). A distance representation of the quasi-symmetry model and related distance models. In Yanai, H., Okada, A., Shigemasu, K. Kano, Y. and Meulman, J.J. (Eds). New developments in Psychometrics. pp. 487- 494. Tokyo: Springer-Verlag. This article may be downloaded for personal use only.
12. De Rooij, M. (2002). Three-way distance models and three-way association. Journal of  Classification, 19, 161-178.This article may be downloaded for personal use only.
13. De Rooij, M. (2001). Distance-Association models for the analysis of repeated transition frequency tables. Statistica Neerlandica, 55, 156-180. This article may be downloaded for personal use only.
14. De Rooij, M. (2001). Distance models for the analysis of transition frequency data. Doctoral thesis. Leiden University.
15. De Rooij, M. and Heiser, W.J. (2000). Triadic distance models for the analysis of asymmetric three-way proximity data. British Journal of Mathematical and Statistical Psychology, 53, 99-119. This article may be downloaded for personal use only. 

Complete list of publications

• De Rooij, M. (2005) Locations and scalings in distance association models for the analysis of change. Paper presented at the 70th annual meeting of the Psychometric Society. Tilburg, NL.
• De Rooij, M. and Anderson, C.J. (2005). Visualising, summarizing and comparing odds ratio structures. Paper presented at the Multi-Regional conference of the International Biometric Society. Leicester, UK. 
• Gower, J.C. and De Rooij, M. (2005). The visualisation of multiplicative interaction. Paper presented at the Multi-Regional conference of the International Biometric Society. Leicester, UK. 
• De Rooij, M (2004). Scaling the odds. Paper presented at the IFCS meeting. Chicago, USA.
• De Rooij, M. (2004). The analysis of change, Newton's law of gravity, and the RC(M)-association model. Paper presented at the Psychometric Society meeting 2004. Monterey, CA, USA
• De Rooij, M. (2003). Statistical Modeling using Euclidean distances. Paper presented at the 54^th session of the International Statistical Institute. August, 2003. Berlin, Germany.

Complete list of talks

• Born 19 december 1969, Hardenberg, THE NETHERLANDS

• 1996: Masters degree in Psychology,  University of Groningen. Specialisations: 1). Psychometrics and Research Methodology; 2) Work, Organizational and Personnel Psychology.

• 2001: PhD in the Social and behavioral Sciences, Leiden University (Cum Laude). Title of thesis: Distance models for the analysis of transition frequencies.

• 2000-2002: Post doctoral Research fellow at the department of psychometrics and research methodology, Leiden University.

• 2002- : Assistent Professor at the department of psychometrics and research methodology, Leiden University.