irtoys - A Collection of Functions Related to Item Response Theory (IRT)
A collection of functions useful in learning and
practicing IRT, which can be combined into larger programs.
Provides basic CTT analysis, a simple common interface to the
estimation of item parameters in IRT models for binary
responses with three different programs (ICL, BILOG-MG, and
ltm), ability estimation (MLE, BME, EAP, WLE, plausible
values), item and person fit statistics, scaling methods (MM,
MS, Stocking-Lord, and the complete Hebaera method), and a rich
array of parametric and non-parametric (kernel) plots.
Estimates and plots Haberman's interaction model when all items
are dichotomously scored.
