Fits Rasch models (RM), linear logistic test models (LLTM), rating scale model
(RSM), linear rating scale models (LRSM), partial credit models (PCM), and
linear partial credit models (LPCM). Missing values are allowed in the data
matrix. Additional features are the ML estimation of the person parameters,
Andersen's LR-test, item-specific Wald test, Martin-Loef-Test, nonparametric
Monte-Carlo Tests, itemfit and personfit statistics including infit and outfit
measures, ICC and other plots, automated stepwise item elimination, simulation
module for various binary data matrices.