“…The dual-objective CD-CAT has been implemented based on two separate psychometric models, one from cognitive diagnostic models (CDMs; de la Torre, 2011; Haertel, 1989;Henson, Templin, & Willse, 2009;Junker & Sijtsma, 2001;Templin & Henson, 2006;von Davier, 2005) and the other from item response theory models (Birnbaum, 1968;Lord, 1980;Lord & Novick, 1968). Research suggests that the unidimensional item response model (IRM) and the DINA model (Haertel, 1989;Junker & Sijtsma, 2001) can adequately fit the same data when attributes are highly correlated or when they are linearly and hierarchically related (Wang et al, 2014). The methods evaluating the relationships among the attributes are discussed in a number of articles: see, for example, Templin, Henson, Templin, and Roussos (2008) for evaluating the correlation between the attributes and Leighton, Gierl, and Hunka (2004) and Templin and Bradshaw (2014) for testing the linear hierarchy among the attributes.…”