Xcalibre Item Parameter Calibration Software for Item Response Theory and Rasch Models

ABSTRACT Item response theory (IRT) and Rasch models have many useful features for test development practitioners and measurement researchers, while some classical test theory (CTT) diagnostics remain useful for understanding items’ properties and sources of model misfit. In a relatively user-friendly fashion, the Xcalibre software estimates a number of dichotomous and polytomous IRT and Rasch models, and provides CTT statistics as well. This article reviews Xcalibre, including a review of the models it calibrates, its scoring methods, diagnostics for model fit analysis, differential item functioning analysis, output file contents, and an overview of setting up the analysis. Examples are provided for a multiple-choice knowledge test, an attitude measure with a rating scale, and an analysis involving anchored item parameters. Screenshots are provided of the graphical user interface screens and sections of the output to help readers understand the look and feel of the software and the types of output it provides.