Probabilistic inference trees for classification and ranking

Abstract

In many applications, an accurate ranking of instances is as important as accurate classification. However, it has been observed that traditional decision trees perform well in classification, but poor in ranking. In this paper, we point out that there is an inherent obstacle for traditional decision trees to achieving both accurate classification and ranking. We propose to understand decision trees from probabilistic perspective, and use probability theory to compute probability estimates and perform classification and ranking. The new model is called probabilistic inference trees (PITs). Our experiments show that the PIT learning algorithm performs well in both ranking and classification. More precisely, it significantly outperforms the state-of-the-art decision tree learning algorithms designed for ranking, such as C4.4 [10] and Ling and Van's algorithm [6], and performs competitively with the traditional decision tree learning algorithms, such as C4.5, in classification. Our research provides a novel algorithm for the applications in which both accurate classification and ranking are desired. © Springer-Verlag Berlin Heidelberg 2006.