chapter  2
28 Pages

Form of Empirical ROCs in Discrimination and Diagnostic Tasks

The ROC, in a sentence, is a graph showing the conditional probability of choosing Alternative A when that alternative occurs (here denoted by h, for “hit”) plotted against the conditional probability of choosing A when Alternative B occurs (here denoted by / , for “false alarm”). Both h and / increase as the tendency to choose Alternative A increases, or as the criterion for choosing A becomes more lenient.