Mahout in Action

Chapter 15. Evaluating and tuning a classifier

This chapter covers

• Basic considerations in evaluating classifiers
• Using the Mahout evaluation API
• Measuring the performance of an SGD classifier
• Common classifier problems and how to diagnose them
• Approaches for tuning a classifier

Because evaluation is so important, it’s built into Mahout at a fundamental level. This chapter deals mainly with stage 2 of the classification process, the evaluation and fine-tuning of a classifier to prepare for deployment and to maintain performance in production. We discuss how classifiers are evaluated at a high level and the details of using the Mahout API for evaluation, and we look at an example of how to use the Mahout API. We also present several examples ...