Developing a diagnostic tool within the diagnostic measurement framework is the optimal approach to obtain multidimensional and classification-based feedback on examinees. However, end users may seek to obtain diagnostic feedback from existing item responses to assessments that have been designed under either the classical test theory or item…

The reliability of scores from four forms of the Test of English as a Foreign Language (TOEFL) was estimated using a hybrid item response theory model. It was found that there was very little difference between overall reliability when the testlet items were assumed to be independent and when their dependence was modeled. (Author/SLD)