Science

A 4-item data set borrowed from <code>ltm</code> package in R,
first example of the <code>grm()</code> function. See more
complete documentation therein.

data

Analysis of dichotomous and polytomous response data using
    unidimensional and multidimensional latent trait models under the Item
    Response Theory paradigm. Exploratory and confirmatory models can be
    estimated with quadrature (EM) or stochastic (MHRM) methods. Confirmatory
    bi-factor and two-tier analyses are available for modeling item testlets.
    Multiple group analysis and mixed effects designs also are available for
    detecting differential item functioning and modelling item and person
    covariates.

Science: Description of Science data

Description

Arguments