robustDIF - Differential Item Functioning Using Robust Scaling
Provides tools for testing differential item functioning
(DIF) and differential test functioning (DTF) in two-group item
response theory models. The package estimates robust scaling
parameters via iteratively reweighted least squares with
Tukey's bisquare loss, and supports Wald-type tests of
item-level and test-level differences from robust scaling
parameters. Inputs can be supplied directly from model
parameter/covariance objects or extracted from fitted 'mirt'
and 'lavaan' models. Methods are described in Halpin (2022)
<doi:10.48550/arXiv.2207.04598>.
