A Collection of Functions Related to Item Response Theory (IRT)
Description
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.