A Collection of Functions Related to Item Response Theory (IRT) R package irtoys version 0.2.2 CRAN Task View: Psychometrics (https://CRAN.R-project.org/view=Psychometrics) A collection of functions useful in learning and practicing IRT, which can be combined into larger programs. Provides basic CTT analysis, a simple common interface to the estimation of item parameters in IRT models for binary responses with three different programs (ICL, BILOG-MG, and ltm), ability estimation (MLE, BME, EAP, WLE, plausible values), item and person fit statistics, scaling methods (MM, MS, Stocking-Lord, and the complete Hebaera method), and a rich array of parametric and non-parametric (kernel) plots. Estimates and plots Haberman's interaction model when all items are dichotomously scored. Software Depends: sm, ltm Suggests: MASS, knitr, rmarkdown Ivailo Partchev <partchev@gmail.com> Comprehensive R Archive Network (CRAN) Ivailo Partchev [aut, cre], Gunter Maris [aut], Tamaki Hattori [ctb] GPL (>= 2) 2022-05-12 application/tgz https://CRAN.R-project.org/package=irtoys doi:10.32614/CRAN.package.irtoys