ABSTRACT

Currently, computer programs such asLOGIST,BILOG-MG,MULTILOG,PARSCALE,TESTFACT, andMicroCAT are available to estimate ability and item parameters. Among these,BILOG-MG (Zimowski et al., 2003; Zimowski, Volume Three, Chapter 22) is commonly used to analyze dichotomous item response data;MULTILOG (Thissen, 1991) andPARSCALE (Muraki & Bock, 2003) are widely used to perform item analysis for both dichotomous and polytomous item response data, with the option to estimate parameters for models such as the generalized partial credit model (GPCM) (Muraki & Muraki, Volume One, Chapter 8). These programs are considered extensions ofBILOG-MG.TESTFACT (Wood, Wilson, Gibbons, Shilling, Muraki et al., 2003) can be used to estimate multidimensional item parameters on dichotomous item responsedata.