Receiver Operating Characteristic (ROC) Analysis

Receiver Operating Characteristic (ROC curves) have been used for years in decision making from signals, such as radar or radiology. Basically they plot the hit rate versus the false alarm rate. They were introduced recently in data mining and machine learning to take into account different misclassification costs, or to deal with skewed class distributions. In particular they help to adapt the extracted model when the training set characteristics differ from the evaluation data. Overall they provide a convenient way to compare classifiers, but also an unexpected way to build better classifiers.