Supplementary Item Response Theory Models R package sirt version 4.2-133 CRAN Task View: Psychometrics (https://CRAN.R-project.org/view=Psychometrics) Supplementary functions for item response models aiming to complement existing R packages. The functionality includes among others multidimensional compensatory and noncompensatory IRT models (Reckase, 2009, <doi:10.1007/978-0-387-89976-3>), MCMC for hierarchical IRT models and testlet models (Fox, 2010, <doi:10.1007/978-1-4419-0742-4>), NOHARM (McDonald, 1982, <doi:10.1177/014662168200600402>), Rasch copula model (Braeken, 2011, <doi:10.1007/s11336-010-9190-4>; Schroeders, Robitzsch & Schipolowski, 2014, <doi:10.1111/jedm.12054>), faceted and hierarchical rater models (DeCarlo, Kim & Johnson, 2011, <doi:10.1111/j.1745-3984.2011.00143.x>), ordinal IRT model (ISOP; Scheiblechner, 1995, <doi:10.1007/BF02301417>), DETECT statistic (Stout, Habing, Douglas & Kim, 1996, <doi:10.1177/014662169602000403>), local structural equation modeling (LSEM; Hildebrandt, Luedtke, Robitzsch, Sommer & Wilhelm, 2016, <doi:10.1080/00273171.2016.1142856>). Software Depends: R (>= 3.5) Imports: CDM, graphics, methods, parallel, pbapply, Rcpp, stats, TAM, utils LinkingTo: pbv, Rcpp, RcppArmadillo Suggests: coda, igraph, lavaan, MASS, Matrix, miceadds, minqa, mirt, mvtnorm, nloptr, optimx, pbivnorm, pbv, psych, sfsmisc, sm, survey Alexander Robitzsch <robitzsch@ipn.uni-kiel.de> Comprehensive R Archive Network (CRAN) Alexander Robitzsch [aut, cre] (ORCID: <https://orcid.org/0000-0002-8226-3132>) GPL (>= 2) 2025-09-27 application/tgz https://CRAN.R-project.org/package=sirt doi:10.32614/CRAN.package.sirt