Which biometric performance metric is characterized by a lower value indicating better accuracy?

Which biometric performance metric is characterized by a lower value indicating better accuracy?

• A. Biometric authentication
• B. FAR
• C. False Rejection Rate (FRR)
• D. Crossover Error Rate (CER)

Answer: (D)

The main idea here is a single-number measure of biometric accuracy that reflects overall performance across operating points. The crossover error rate is the point at which the two types of errors, false accept and false reject, are equal. The value at that crossing is a summary of how well the system balances security and usability overall. A smaller crossover error rate means the system achieves better accuracy at the threshold where these errors meet, so performance is better across thresholds. This is why the crossover error rate is described as having a lower value indicating better accuracy. While false accept and false reject rates also improve as they get smaller, they represent performance at a specific threshold rather than a single threshold-independent summary like CER.

The main idea here is a single-number measure of biometric accuracy that reflects overall performance across operating points. The crossover error rate is the point at which the two types of errors, false accept and false reject, are equal. The value at that crossing is a summary of how well the system balances security and usability overall. A smaller crossover error rate means the system achieves better accuracy at the threshold where these errors meet, so performance is better across thresholds. This is why the crossover error rate is described as having a lower value indicating better accuracy. While false accept and false reject rates also improve as they get smaller, they represent performance at a specific threshold rather than a single threshold-independent summary like CER.