Abstract
Item response theory (IRT) models are the central tools in modern measurement and advanced psychometrics. We offer a MATLAB IRT modeling (IRTm) toolbox that is freely available and that follows an explicit design matrix approach, giving the end user control and flexibility in building a model that goes beyond standard models, such as the Rasch model (Rasch, 1960) and the two-parameter logistic model. As such, IRTm allows for a large variety of unidimensional IRT models for binary responses, the incorporation of additional person and item information, and deviations from common model assumptions. An exclusive key feature of the toolbox is the inclusion of copula IRT models to handle local item dependencies. Two appendixes for this report, containing example code and information on the general copula IRT in IRTm, may be downloaded from brm.psychonomic-journals.org/content/supplemental.
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Preparation of this article was supported in part by the Fund for Scientific Research Flanders (F.W.O.) Grant No. G.0148.04, by the K. U. Leuven Research Council Grant No. GOA/2005/04, and by the Cito Psychometric Research and Knowledge Center.
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Braeken, J., Tuerlinckx, F. Investigating latent constructs with item response models: A MATLAB IRTm toolbox. Behavior Research Methods 41, 1127–1137 (2009). https://doi.org/10.3758/BRM.41.4.1127
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DOI: https://doi.org/10.3758/BRM.41.4.1127