md.mixed

This dataset includes multidimensional 3PL and multidimensional generalized partial
credit model item parameters for two groups modeled with four dimensions.  The item
parameters were estimated based on item responses provided with BMIRT (Yao, 2008).

datasets

Item response theory based methods are used to compute
linking constants and conduct chain linking of unidimensional
or multidimensional tests for multiple groups under a common
item design.  The unidimensional methods include the Mean/Mean,
Mean/Sigma, Haebara, and Stocking-Lord methods for dichotomous
(1PL, 2PL and 3PL) and/or polytomous (graded response, partial
credit/generalized partial credit, nominal, and multiple-choice
model) items.  The multidimensional methods include the least
squares method and extensions of the Haebara and Stocking-Lord
method using single or multiple dilation parameters for
multidimensional extensions of all the unidimensional
dichotomous and polytomous item response models.  The package
also includes functions for importing item and/or ability
parameters from common IRT software, conducting IRT true score
and observed score equating, and plotting item response
curves/surfaces, vector plots, information plots, and comparison
plots for examining parameter drift.

Jonathan Weeks

plink

IRT Separate Calibration Linking Methods

md.mixed function

A list of length two. There are two matrices in the first list element that correspond
to form.x and form.y tests respectively.  The second list element identifies the 
number of response categories for each item.  All of the items are common items.  There
is no location parameter for the polytomous items.

md.mixed: Multidimensional Mixed-Format Tests

Description

Usage

Arguments

Format