Package: irtlink
Title: IRT Linking and Linking Error Estimation Across Time Points and
        Groups
Version: 0.1.0
Authors@R: 
    person("Oskar", "Engels", email = "engels@leibniz-ipn.de",
           role = c("aut", "cre"),
           comment = c(ORCID = "0009-0008-3325-0352"))
Description: Estimation of trends in the mean and standard deviation of
        latent ability distributions across the time points of
        educational assessments, and of ability distribution
        differences across linked groups, for unidimensional item
        response theory (IRT) models (1PL, 2PL, 3PL, partial credit,
        and generalized partial credit). Groups connected through
        common items, with independent or dependent person samples, are
        calibrated on an internal marginal maximum likelihood EM
        engine, separately, concurrently, with fixed item parameters,
        or with regularized calibration. Linking methods include
        mean-mean and mean-geometric mean linking, Haberman linking
        (Haberman, 2009, <doi:10.1002/j.2333-8504.2009.tb02197.x>) with
        robust Lp loss and a pairwise variant (Robitzsch, 2025,
        <doi:10.3390/appliedmath5010007>), and the response function
        methods of Haebara and Stocking-Lord. Under differential item
        functioning (DIF), the linked estimates depend on the selected
        common items, and the package estimates this linking error
        together with the standard error by jackknife and sandwich
        estimators, including bias-corrected variants (Robitzsch, 2024,
        <doi:10.3390/stats7030036>). RMSD and likelihood-ratio DIF
        diagnostics with iterative purification are included.
License: GPL (>= 3)
URL: https://github.com/oskarengels/irtlink
BugReports: https://github.com/oskarengels/irtlink/issues
Encoding: UTF-8
Imports: graphics, grDevices, parallel, Rcpp, stats, utils
LinkingTo: Rcpp
Suggests: knitr, rmarkdown, testthat (>= 3.1.7)
VignetteBuilder: knitr
Config/testthat/edition: 3
NeedsCompilation: yes
Packaged: 2026-10-16 17:50:33 UTC; root
Author: Oskar Engels [aut, cre] (ORCID:
        <https://orcid.org/0009-0008-3325-0352>)
Maintainer: Oskar Engels <engels@leibniz-ipn.de>
Repository: https://cran.r-universe.dev
Date/Publication: 2026-10-16 13:30:02 UTC
RemoteUrl: https://github.com/cran/irtlink
RemoteRef: HEAD
RemoteSha: 3c2dd8ba15a445c78dea7033f2949629d7e42db9
