01208nas a2200109   4500008004100000245010200041210006900143260009700212520065700309100001500966856011700981       2009                        eng d00aThe MEDPRO project: An SBIR project for a comprehensive IRT and CAT software system: IRT software0 aMEDPRO project An SBIR project for a comprehensive IRT and CAT s  aD. J. Weiss (Ed.), Proceedings of the 2009 GMAC Conference on Computerized Adaptive Testing.3 aIRTPRO (Item Response Theory for Patient-Reported Outcomes) is an entirely new application for item 
calibration and test scoring using IRT. IRTPRO implements algorithms for maximum likelihood estimation of item parameters (item calibration) for several unidimensional and multidimensional item response theory (IRT) models for dichotomous and polytomous item responses. In addition, the software provides computation of goodness-of-fit indices, statistics for the diagnosis of local dependence and for the detection of differential item functioning (DIF), and IRT scaled scores. This paper illustrates the use, and some capabilities, of the software.1 aThissen, D  uhttp://mail.iacat.org/content/medpro-project-sbir-project-comprehensive-irt-and-cat-software-system-irt-software