The information system, nowadays, is useful to backup and process information. However, for some reasons such as updating and storing, the information has some redundant attributes; therefore, it is difficult to explore knowledge. In addition, the attribute reductions are essential requirements for mining knowledge. There are many types of attribute reduction and decision rules which have been proposed in data mining. In this note, we propose a heuristic algorithm to find the reduction of a decision table based on the discernibility matrix.

information systems, discernibility matrix, the reduction sets