Diagnostic Classification Models

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.

Diagnostic classification models (DCMs) have recently become very popular both for research purposes and for real testing endeavors for student assessment. A plethora of DCM models give researchers and practitioners a wide range of options for student diagnosis and classification. One intriguing option that some DCM models offer is the possibility of examining the nature of the interactions among the attributes underlying a skill. Attributes in second/foreign language (L2) may interact with each other in a compensatory/non-compensatory manner. Subskill/attribute relationship has been studied using diagnostic classification models. The present study provides a mini review of the DCM studies on the attribute relationships in L2 reading, listening, and writing. The criteria based on which interaction between the attributes have been inferred are reviewed. The results showed that the majority of DCM studies have investigated reading comprehension and more studies are required on the productive skills of writing and speaking. Furthermore, suggestions for future studies are provided.