iDIFr: Intersectional Differential Item Functioning Analysis

A toolkit for detecting Differential Item Functioning (DIF) using Logistic Regression (LR) as described in Swaminathan and Rogers (1990) <doi:10.1111/j.1745-3984.1990.tb00754.x>, the IRT Likelihood Ratio Test (LRT) following Thissen, Steinberg & Wainer (1993, ISBN:0-8058-0972-4), and model-based recursive partitioning (MOB) as implemented in 'strucchange' following Strobl, Kopf and Zeileis (2015) <doi:10.1007/s11336-013-9388-3>. Designed for both standard two-group and intersectional multi-group designs, 'iDIFr' prioritises effect size reporting alongside statistical significance, clear guidance on group construction, and interpretable output suitable for applied testing contexts. Built-in Intersectional Contrast Analysis (ICA) classifies items as amplified, pure-intersection, obscured, or none by comparing single-variable and intersectional analyses.

Version: 1.0.1
Depends: R (≥ 4.1.0)
Imports: Rcpp (≥ 1.0.0), generics, parallel, stats, cli, dplyr, ggplot2, rlang, strucchange
LinkingTo: Rcpp
Suggests: testthat (≥ 3.0.0), knitr, rmarkdown, openxlsx
Published: 2026-06-08
DOI: 10.32614/CRAN.package.iDIFr (may not be active yet)
Author: Thomas Rogers [aut, cre]
Maintainer: Thomas Rogers <thomas.rogers at britishcouncil.org>
BugReports: https://github.com/thmsrgrs/iDIFr/issues
License: MIT + file LICENSE
URL: https://github.com/thmsrgrs/iDIFr
NeedsCompilation: yes
Materials: README, NEWS
CRAN checks: iDIFr results

Documentation:

Reference manual: iDIFr.html , iDIFr.pdf
Vignettes: Getting started with iDIFr (source, R code)

Downloads:

Package source: iDIFr_1.0.1.tar.gz
Windows binaries: r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries: r-release (arm64): not available, r-oldrel (arm64): not available, r-release (x86_64): iDIFr_1.0.1.tgz, r-oldrel (x86_64): not available

Linking:

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