Simulation Studies for Evaluating

The attribute hierarchy method (AHM) (Leighton, Gierl, & Hunka, 2004), which is based on the assumption that test items can be described by a set of hierarchically ordered attributes, is designed to estimate examinees’ level of competency as well as their profiles for mastering a set of attributes. The AHM, by incorporating the assumption of attribute dependency, brings an important cognitive property into cognitive diagnostic testing. This study used simulated response vectors to evaluate the performance of the two classification methods (method A and B) for the AHM. The performance of the two classification methods was evaluated at the attribute pattern level and the individual attribute level, respectively. Our results suggest that classification method B outperforms method A at both the attribute pattern and the individual attribute level. In addition, the performance of two methods at the individual attribute level is considerably higher than their performance at the attribute pattern level.