Receiver operating characteristic (ROC) curves for contiguous point analysis and single point analysis. In each panel, the false-positive rate is estimated by the average of leave-one-out cross-validation on 62 normal females (2X). The true-positive rate is estimated using 1X, 3X, 4X and 5X samples. With a range of p-value thresholds, a series of false-positive rates and true-positive rates can be calculated which form the basis of the ROC curves. Panels (c) and (d) are enlargements of (a) and (b), respectively, with the false-positive rate extending only to 1 per cent rather than 100 per cent.