AUTHOR=Cai Yan , Tu Dongbo , Ding Shuliang TITLE=Theorems and Methods of a Complete Q Matrix With Attribute Hierarchies Under Restricted Q-Matrix Design JOURNAL=Frontiers in Psychology VOLUME=Volume 9 - 2018 YEAR=2018 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2018.01413 DOI=10.3389/fpsyg.2018.01413 ISSN=1664-1078 ABSTRACT=The design of test Q matrix can directly influence the classification accuracy for a cognitive diagnostic assessment. In this paper, we focus on the Q matrix design when attribute hierarchies are known before test development. A complete Q matrix design is proposed and theorems are presented to show that it is a necessary and sufficient condition to guarantee the identifiability of ideal response pattern. The proposed Q matrix design turns out to be the key condition to guarantee the classification accuracy for a family of conjunctive diagnostic models. The proposed procedures for a complete Q matrix design with attribute hierarchies can serve as guidelines for test blueprint development before item writing in a cognitive diagnostic assessment.