Author_Institution :
Dept. of Comput. Sci., City Univ. of Hong Kong, Hong Kong, China
Abstract :
A key issue in decision tree (DT) induction with continuous valued attributes is to design an effective strategy for splitting nodes. The traditional approach to solving this problem is adopting the candidate cut point (CCP) with the highest discriminative ability, which is evaluated by some frequency based heuristic measures. However, such methods ignore the class permutation of examples in the node, and they cannot distinguish the CCPs with the same or similar frequency information, thus may fail to induce a better and smaller tree. In this paper, a new concept, i.e., segment of examples, is proposed to differentiate the CCPs with same frequency information. Then, a new hybrid scheme that combines the two heuristic measures, i.e., frequency and segment, is developed for splitting DT nodes. The relationship between frequency and the expected number of segments, which is regarded as a random variable, is also given. Experimental comparisons demonstrate that the proposed scheme is not only effective to improve the generalization capability, but also valid to reduce the size of the tree.
Keywords :
decision trees; learning by example; CCP; DT induction; candidate cut point; class permutation; continuous valued attributes; discriminative ability; frequency based heuristic measures; frequency information; random variable; segment based decision tree induction; splitting nodes; Algorithm design and analysis; Decision trees; Entropy; Frequency measurement; Information entropy; Supervised learning; Classification; continuous valued attributes; decision tree (DT) induction; segment;