Assessment of Class Predictions

Abstract

The previous chapter focused on models that make numeric predictions. This chapter deals with models whose goal is classification. It must be understood that the distinction is not always clear. In particular, almost no models can be considered to be pure classifiers. Most classification models make a numeric prediction (of a scalar or a vector) and then use this numeric prediction to define a classification decision. Thus, the real distinction is not in the nature of the model but in the nature of the ultimate goal. The implications of this fact will resound throughout the chapter.