关键词: 分辨矩阵, 属性重要度, 规则提取, 属性约简

Abstract: The attribute reduction and value reduction of rough set are discussed in this paper.The discernibility matrix is extended to value reduction and the attribute significance is redefined based on attribute dependence.A algorithm for classification rule extraction based on discernibility matrix and attribute significance is proposed，which keeps the same classification ability，comes to the smallest attribute reduction and gets the effective rules after the value reduction.Compared with the existed algorithm，less time complexity and less space complexity are acquired with this method.Finally，experiment sets on clothing sales verify the effectiveness of the algorithm.

Key words: discernibility matrix, attribute significance, rule generation, attribute reduction