Multiple UniDimensional unFOLDing

Nonparametric unfolding item response theory (IRT) model for dichotomous data (see W.H. Van Schuur (1984). Structure in Political Beliefs: A New Model for Stochastic Unfolding with Application to European Party Activists, and W.J.Post (1992). Nonparametric Unfolding Models: A Latent Structure Approach). The package implements MUDFOLD (Multiple UniDimensional unFOLDing), an iterative item selection algorithm that constructs unfolding scales from dichotomous preferential-choice data without explicitly assuming a parametric form of the item response functions. Scale diagnostics from Post(1992) and estimates for the person locations proposed by Johnson(2006) and Van Schuur(1984) are also available. This model can be seen as the unfolding variant of Mokken(1971) scaling method.


Reference manual

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1.1.1 by Spyros Balafas, 2 months ago

Browse source code at

Authors: Spyros Balafas [aut, cre] , Wim Krijnen [aut] , Wendy Post [ctb] , Ernst Wit [aut]

Documentation:   PDF Manual  

Task views: Psychometric Models and Methods

GPL (>= 2) license

Imports gtools, boot, zoo, ggplot2, reshape2, stats, utils

See at CRAN