Package: IRTest 2.2.0

Seewoo Li

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. 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.

Authors:Seewoo Li [aut, cre, cph]

IRTest_2.2.0.tar.gz
IRTest_2.2.0.zip(r-4.7)IRTest_2.2.0.zip(r-4.6)IRTest_2.2.0.zip(r-4.5)
IRTest_2.2.0.tgz(r-4.6-any)IRTest_2.2.0.tgz(r-4.5-any)
IRTest_2.2.0.tar.gz(r-4.7-any)IRTest_2.2.0.tar.gz(r-4.6-any)
IRTest_2.2.0.tgz(r-4.6-emscripten)
manual.pdf |manual.html✨
card.svg |card.png
IRTest/json (API)
NEWS

# Install 'IRTest' in R:

install.packages('IRTest', repos = c('https://seewooli.r-universe.dev', 'https://cloud.r-project.org'))

Bug tracker:https://github.com/seewooli/irtest/issues

On CRAN:

4.41 score 2 stars 13 scripts 555 downloads 19 exports 55 dependencies

Last updated from:2527c143df. Checks:9 OK. Indexed: yes.

Target	Result	Time
linux-devel-x86_64	OK	187
source / vignettes	OK	366
linux-release-x86_64	OK	178
macos-release-arm64	OK	155
macos-oldrel-arm64	OK	177
windows-devel	OK	132
windows-release	OK	124
windows-oldrel	OK	143
wasm-release	OK	106

Exports:adaptive_test best_model cat_clps coef_se DataGeneration dist2 factor_score inform_f_item inform_f_test IRTest_Cont IRTest_Dich IRTest_Mix IRTest_Poly item_fit latent_distribution original_par_2GM plot_item recategorize reliability

Dependencies:askpass betafunctions cli clipr cpp11 crayon credentials curl dcurver desc dplyr farver fs generics gert ggplot2 gh gitcreds glue gtable httr2 ini isoband jsonlite labeling lifecycle magrittr openssl pillar pkgconfig purrr R6 rappdirs RColorBrewer Rcpp RcppArmadillo rlang rprojroot rstudioapi S7 scales stringi stringr sys tibble tidyr tidyselect usethis utf8 vctrs viridisLite whisker withr yaml zip

IRT without the normality assumption

Rendered fromvignette_for_IRTest.Rmdusingknitr::rmarkdownon May 15 2026.

Last update: 2024-05-31
Started: 2022-07-27

Citation

Development and contributors

Readme and manuals

Help Manual

Help page	Topics
Ability parameter estimation with fixed item parameters	adaptive_test
Model comparison	anova.IRTest
Selecting the best model	best_model
A recommendation for category collapsing of items based on item parameters	cat_clps
Extract Standard Errors of Model Coefficients	coef_se
Extract Model Coefficients	coef.IRTest
Generating an artificial item response dataset	DataGeneration
Re-parameterized two-component normal mixture distribution	dist2
Estimated factor scores	factor_score
Item information function	inform_f_item
Test information function	inform_f_test
Item and ability parameters estimation for continuous response items	IRTest_Cont
Item and ability parameters estimation for dichotomous items	IRTest_Dich
Item and ability parameters estimation for a mixed-format item response data	IRTest_Mix
Item and ability parameters estimation for polytomous items	IRTest_Poly
Item fit diagnostics	item_fit
Latent density function	latent_distribution
Extract Log-Likelihood	logLik.IRTest
Recovering original parameters of two-component Gaussian mixture distribution from re-parameterized values	original_par_2GM
Plot of item response functions	plot_item
Plot of the estimated latent distribution	plot.IRTest
Printing the result	print.IRTest
Printing the summary	print.IRTest_summary
Recategorization of data using a new categorization scheme	recategorize
Marginal reliability coefficient of IRT	reliability
Summary of the results	summary.IRTest