Diagnostic classification models (aka cognitive or skills diagnosis models) have shown great promise for evaluating mastery on a multidimensional profile of skills as assessed through examinee responses, but continued development and application of these models has been hindered by a lack of readily available software. In this article we…

High-stakes decisions for the instruction and assessment of English language learner (ELL) students are made based on the premise that ELL classification is a valid dichotomy that distinguishes between those who are proficient in the use of the English language and those who are not. However, recent research findings draw a vague picture of the…