Supported by the National Natural Science Foundation of China (30860084,60673014,60263005);the Backbone Young Teachers Foundation of Fujian Normal University(2008100244);the Department of Education Foundation of Fujian Province (ZA09047)~~
Reduced Q-matrix (Qr matrix) plays an important role in the rule space model (RSM) and the attribute hierarchy method (AHM). Based on the attribute hierarchy, a valid/invalid item is defined. The judgment method...