Text Categorization: Evaluation

This chapter is concerned with the schemes of evaluating text categorization systems. We adopt the two measures, recall and precision, which are used for evaluating information retrieval systems, and they are integrated into F1 measure. A text categorization task is decomposed into binary classifications, and the F1 measure is applied to each binary classification. There are two schemes of averaging F1 measures which correspond to binary classifications: micro-averaging and macro-averaging. In this chapter, we describe the text collection for evaluating text categorization systems, evaluation measures, and the schemes of comparing two approaches.