mudfold: 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.

Version: 1.1.21
Depends: R (≥ 3.3.3)
Imports: boot, glmnet, mgcv, ggplot2, zoo, reshape2, stats, utils, grDevices, broom, dplyr, graphics
Published: 2022-11-24
DOI: 10.32614/CRAN.package.mudfold
Author: Spyros Balafas [aut, cre], Wim Krijnen [aut], Wendy Post [ctb], Ernst Wit [aut]
Maintainer: Spyros Balafas <sp.balafas at>
License: GPL-2 | GPL-3 [expanded from: GPL (≥ 2)]
NeedsCompilation: no
In views: Psychometrics
CRAN checks: mudfold results


Reference manual: mudfold.pdf


Package source: mudfold_1.1.21.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
macOS binaries: r-release (arm64): mudfold_1.1.21.tgz, r-oldrel (arm64): mudfold_1.1.21.tgz, r-release (x86_64): mudfold_1.1.21.tgz, r-oldrel (x86_64): mudfold_1.1.21.tgz
Old sources: mudfold archive


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