Diagnostic Test Construction: Insights from Cognitive Diagnostic Modeling

Although Diagnostic Classification Models (DCMs) were introduced to education system decades ago, it seems that these models were not employed for the original aims upon which they had been designed. Using DCMs has been mostly common in analyzing large-scale non-diagnostic tests and these models have been rarely used in developing Cognitive Diagnostic Assessment (CDA) from scratch. Despite the prevalence of "retrofitting" CDA studies, "true" applications of CDA are believed to be rare since, firstly, a coherent framework to conduct such studies had not been available and, secondly, researchers were not able to analyze various DCMs according to the same model fit indices and criteria. This paper presents a summary of different types of DCMs and reviews "true" and "retrofitting" CDA studies. Having examined the limitations of previous CDA studies, the present study argues for the implication and application of Ravand and Baghaei's (2019) framework to conduct "true" CDA studies. This framework is of importance since not only does it fit into prominent frameworks in education assessment such as Cognitive Design System and Assessment Triangle, but also it can provide test-developers with practical steps in conducting valid cognitive diagnostic tests.