Interactive decision tree learning and decision rule extraction based on the imbtreeentropy and imbtreeauc packages

Abstract

This paper presents two new R packages ImbTreeEntropy and ImbTreeAUC for building decision trees, including their interactive construction and analysis, which is a highly regarded feature for field experts who want to be involved in the learning process. ImbTreeEntropy function-ality includes the application of generalized entropy functions, such as Renyi, Tsallis, Shar-ma-Mittal, Sharma-Taneja and Kapur, to measure the impurity of a node. ImbTreeAUC provides non-standard measures to choose an optimal split point for an attribute (as well the optimal attribute for splitting) by employing local, semi-global and global AUC measures. The contribution of both packages is that thanks to interactive learning, the user is able to construct a new tree from scratch or, if required, the learning phase enables making a decision regarding the optimal split in ambiguous situations, taking into account each attribute and its cut-off. The main difference with existing solutions is that our packages provide mechanisms that allow for analyzing the trees’ structures (several trees simultaneously) that are built after growing and/or pruning. Both packages support cost-sensitive learning by defining a misclassification cost matrix, as well as weight-sensitive learning. Additionally, the tree structure of the model can be represented as a rule-based model, along with the various quality measures, such as support, confidence, lift, con-viction, addedValue, cosine, Jaccard and Laplace.