ROC curves corresponding to 100 random splittings of the samples of labelled sources (with no flag) used for classifier building. Performance for sources with no flag were estimated using the test samples (green curves). Specific performance for flagged sources were estimated using the samples of labelled sources with a flag (red curves). The left and right columns show respectively the results for the BDT and MLP classifiers. Results for case A high galactic latitude, case A low galactic latitude and case B are shown in rows a), b), and c), respectively.