The performance of the limited-information statistic M 2 for diagnostic classification models (DCMs) is under-investigated in the current literature. Specifically, the investigations of M 2 for specific DCMs rather than general modeling frameworks are needed. This article aims to demonstrate the usefulness of M 2 in hierarchical diagnostic classification models (HDCMs). The performance of M 2 in evaluating the fit of HDCMs was investigated in the presence of four types of attribute hierarchies. Two simulation studies were conducted to examine Type I error rates and statistical power of M 2 under different simulation conditions, respectively. The findings suggest acceptable Type I error rates control of M 2 as well as high statistical power under the conditions of a Q-matrix misspecification and the DINA model misspecification. The data of Examination for the Certificate of Proficiency in English (ECPE) were used to empirically illustrate the suitability of M 2 in practice.
Keywords: absolute fit test; attribute hierarchies; diagnostic classification models; goodness-of-fit; limited-information test statistics.