Figure 6

False-positive rate (1 - specificity) versus true-positive rate (sensitivity). The bold curve was obtained on the basis of all patients, whereas the curves above and below were obtained for the good and the poor candidates, respectively. Approximately halving the standard deviation of the measurement error yielded the dotted curves. By increasing the threshold of the assumed “gold standard” method from 2 dB to 5 dB, the bold curve turned into the curve bounding the gray area in the background.