CMC (Cumulative Match Characteristic)

The Cumulative Match Characteristic (CMC) is a metric used to evaluate the accuracy of a system—such as a facial recognition or identification system—by measuring how often the correct match appears within the top ranks of a list of potential matches. For example, if a system identifies a person correctly within its top-1, top-5, or top-10 suggestions, the CMC curve shows the probability of correct identification at each rank threshold. It helps assess how effectively the system narrows down options and how quickly it can find the correct match among many candidates.