IRTest: Parameter Estimation of Item Response Theory with Estimation of Latent Distribution

Item response theory (IRT) parameter estimation using marginal maximum likelihood and expectation-maximization algorithm (Bock & Aitkin, 1981 <doi:10.1007/BF02293801>). Within parameter estimation algorithm, several methods for latent distribution estimation are available (Li, 2022 <>). Reflecting some features of the true latent distribution, these latent distribution estimation methods can possibly enhance the estimation accuracy and free the normality assumption on the latent distribution.

Version: 1.11.0
Depends: R (≥ 2.10)
Imports: betafunctions, dcurver, ggplot2
Suggests: knitr, rmarkdown, testthat (≥ 3.0.0), V8, gridExtra
Published: 2023-09-19
Author: Seewoo Li [aut, cre, cph]
Maintainer: Seewoo Li <cu at>
License: GPL (≥ 3)
NeedsCompilation: no
Citation: IRTest citation info
Materials: README NEWS
CRAN checks: IRTest results


Reference manual: IRTest.pdf
Vignettes: IRT without the normality assumption


Package source: IRTest_1.11.0.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
macOS binaries: r-release (arm64): IRTest_1.7.0.tgz, r-oldrel (arm64): IRTest_1.7.0.tgz, r-release (x86_64): IRTest_1.7.0.tgz, r-oldrel (x86_64): IRTest_1.11.0.tgz
Old sources: IRTest archive


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