Xcalibre™ 4 represents the leading edge in software for item response theory (IRT) analysis of assessments. Xcalibre™ 4 calibrates your test using 4 dichotomous and 5 polytomous IRT models, and produces professional reports summarizing the analysis, complete with embedded graphics and tables. It also includes differential item functioning and IRT linking. Xcalibre™ 4 is the most user-friendly IRT software available, with a purely point-and-click interface - no programming code!