Evaluating cost-sensitive unsolicited bulk email categorization

Abstract

In the recent years, Unsolicited Bulk Email has became an increasingly important problem, with a big economic impact. In this paper, we discuss cost-sensitive Text Categorization methods for UBE filtering. In concrete, we have task (C4.5, Naive Bayes, PART. Support Vector Machines and Rocchio), made cost sensitive through several methods (Threshold Optimization, Instance Weighting, and Meta-Cost). We have used the Receiver Operating Characteristic Convex Hull method for the evaluation, that best suits classification problems in which target conditions are not known, as it is the case. Our results do not show a dominant algorithm nor method for making algorithms cost-sensitive, but are the best reported on the test collection used, and approach real-world hand-crafted classifiers accuracy.