Henk Kelderman

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Measurement bias refers to systematic differences across subpopulations in the relation between observed test scores and the latent variant underlying the test scores. Comparisons of subpopulations with the same score on the latent variable can be expected to have the same observed test score. Measurement invariance is therefore one of the key issues in(More)
Investigating sources of within-and between-group differences and measurement invariance (MI) across groups is fundamental to any meaningful group comparison based on observed test scores. It is shown that by placing certain restrictions on the multigroup confirmatory factor model, it is possible to investigate the hypothesis that within-and between-group(More)
Jensen has posited a research method to investigate group differences in cognitive tests. This method consists of first extracting a general intelligence factor by means of exploratory factor analysis. Secondly, similarity of factor loadings across groups is evaluated in an attempt to ensure that the same constructs are measured. Finally, the correlation is(More)
The efficacy of treatments for depression is often measured by comparing observed total scores on self-report inventories, in both clinical practice and research. However, the occurrence of response shifts (changes in subjects' values, or their standards for measurement) may limit the validity of such comparisons. As most psychological treatments for(More)
BACKGROUND The Amblyopia and Strabismus Questionnaire (A&SQ) was previously developed to assess quality of life (QoL) in amblyopia and/or strabismus patients. Here, factor analysis with Varimax rotation was employed to confirm that the questions of the A&SQ correlated to dimensions of quality of life (QoL) in such patients. METHODS Responses on the A&SQ(More)
This paper introduces the Mixed Birnbaum model with collateral information. A simulation study is conducted to evaluate parameter estimation for this model. More specifically, the gain of incorporating collateral information into the model is investigated. The results show that the standard errors as well as latent class assignment can benefit substantially(More)
The multilevel model of change and the latent growth model are flexible means to describe all sorts of population heterogeneity with respect to growth and development, including the presence of sub-populations. The growth mixture model is a natural extension of these models. It comes at hand when information about sub-populations is missing and researchers(More)
A fully pigtailed and packaged ultra-compact reconfigurable 4-channel optical add-drop multiplexer is shown based on SiO 2 /Si 3 N 4 microring resonators. Measurements demonstrate full add/drop capability for 40 Gbit/s datasignal as well as the ability to multicast a channel. Introduction When the optical fiber networks are emerging towards the end user's(More)
A method is proposed for the detection of item bias with respect to observed or unobserved subgroups. The method uses quasi-loglinear models for the incomplete subgroup x test score x Item 1 × • • • x item k contingency table. If subgroup membership is unknown the models are Haberman's incomplete-latent-class models. The (conditional) Rasch model is(More)