eRm: Extended Rasch Modeling

eRm fits Rasch models (RM), linear logistic test models (LLTM), rating scale model (RSM), linear rating scale models (LRSM), partial credit models (PCM), and linear partial credit models (LPCM). Missing values are allowed in the data matrix. Additional features are the ML estimation of the person parameters, Andersen's LR-test, item-specific Wald test, Martin-Loef-Test, nonparametric Monte-Carlo Tests, itemfit and personfit statistics including infit and outfit measures, various ICC and related plots, automated stepwise item elimination, simulation module for various binary data matrices. An eRm platform is provided at R-forge (see URL).

Version: 0.15-4
Depends: R (≥ 3.0.0)
Imports: graphics, stats, methods, MASS, splines, Matrix
Suggests: lattice
Published: 2014-02-05
Author: Patrick Mair [cre, aut], Reinhold Hatzinger [aut], Marco J. Maier [aut]
Maintainer: Patrick Mair <mair at>
License: GPL-2
NeedsCompilation: yes
Materials: NEWS
In views: Multivariate, Psychometrics
CRAN checks: eRm results


Reference manual: eRm.pdf
Vignettes: eRm Basics
Package source: eRm_0.15-4.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
OS X Snow Leopard binaries: r-release: eRm_0.15-4.tgz, r-oldrel: eRm_0.15-4.tgz
OS X Mavericks binaries: r-release: eRm_0.15-4.tgz
Old sources: eRm archive

Reverse dependencies:

Reverse suggests: sirt