Cai Sheng-zhen

The judgment method of valid item and its application

Rule space model (RSM) and attribute hierarchy method (AHM) have been research focuses in cognitive diagnosis. Reduced Q-matrix (incidence matrix between attributes and items), which named Qr matrix, plays an important role in RSM and AHM. The column vector of Qr matrix should satisfy an attribute hierarchy, and the vector is called valid item. Studying attribute hierarchy, the judgment method of valid item is proposed. The method is applied to RSM and AHM, and empirical evidence showed that it performed very well.