The purpose of this paper is to briefly introduce two most common applications of multiple group item response theory (IRT) models, namely detecting differential item functioning (DIF) analysis and nonequivalent group score linking with a simultaneous calibration. We illustrate how to conduct those analyses using the "Stata" item…

The nonequivalent groups anchor test (NEAT) design is often used to scale item parameters from two different test forms. A subset of items, called the anchor items or common items, are administered as part of both test forms. These items are used to adjust the item calibrations for any differences in the ability distributions of the groups taking…

The Maryland Functional Testing Program (MFTP) uses the Rasch model as the statistical framework for the analysis of test items and scores. This paper is designed to assist the reader in developing an understanding of the fit statistics in the Rasch model. Background materials on application of the Rasch model in statistical analysis of the MFTP…