In the past twenty-five years, assessment developers and educators have been seeking ways to make assessments more informative and to advance understandings of students' cognitive processes (Ercikan, 2006; Leighton & Gierl, 2007). Demands for personalized formative assessment feedback have stimulated interest in the application of diagnostic classification models to educational tests (Choi, Rupp, & Pan, 2012; Huff & Goodman, 2007). Statistical latent variable models provide multidimensional classifications of students' learning competencies (Rupp & Mislevy, 2007; Rupp & Templin, 2008). One approach to the measurement of multiple dimensions is diagnostic classification models (DCMs). Validity evidence is necessary for DCMs given the important inferences and possible decisions made from the estimated skill profiles. Further research is necessary to provide greater confidence that DCMs can accurately classify students' skills. This study hopes to add to the body of validity literature that will help demonstrate whether or not the mastery classification status is a valid interpretation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]