CBP CBP Biometric Performance Metrics and Testing 1 — Questions and Answers
Question 1: What does the False Acceptance Rate (FAR) measure in a biometric system?
- The rate at which imposters are incorrectly accepted (Correct answer)
- The rate at which legitimate users are rejected
- The rate at which enrollments fail
- The rate at which the sensor malfunctions
Correct answer: The rate at which imposters are incorrectly accepted
FAR measures the frequency with which unauthorized individuals are incorrectly accepted by the biometric system.
Question 2: What does the False Rejection Rate (FRR) indicate in biometric performance evaluation?
- The percentage of impostors accepted
- The percentage of legitimate users incorrectly denied access (Correct answer)
- The threshold score for a match decision
- The time taken to process a biometric sample
Correct answer: The percentage of legitimate users incorrectly denied access
FRR is the rate at which genuine users are incorrectly rejected, directly impacting user convenience and system usability.
Question 3: The Equal Error Rate (EER) is the point at which:
- FAR equals 0%
- FRR equals 0%
- FAR and FRR are equal (Correct answer)
- Throughput is maximized
Correct answer: FAR and FRR are equal
The EER is the threshold point where the False Acceptance Rate and False Rejection Rate are equal, commonly used to compare system accuracy.
Question 4: Which metric specifically measures a biometric system's ability to correctly identify enrolled users across a database?
- Failure to Enroll Rate (FTE)
- Identification Rate (Rank-1) (Correct answer)
- False Match Rate (FMR)
- Failure to Acquire Rate (FTA)
Correct answer: Identification Rate (Rank-1)
The Rank-1 Identification Rate measures the probability that the correct identity appears as the top match in a 1-to-many search.
Question 5: What is the Failure to Enroll Rate (FTE) in biometrics?
- The rate at which enrolled users are rejected during verification
- The rate at which individuals cannot be enrolled due to insufficient biometric quality (Correct answer)
- The percentage of false matches in a database
- The frequency of sensor calibration failures
Correct answer: The rate at which individuals cannot be enrolled due to insufficient biometric quality
FTE represents the proportion of users whose biometric samples do not meet minimum quality standards for enrollment.
Question 6: In a Receiver Operating Characteristic (ROC) curve for biometrics, what do the axes typically represent?
- FAR on X-axis and FRR on Y-axis (Correct answer)
- FRR on X-axis and FAR on Y-axis
- Throughput on X-axis and accuracy on Y-axis
- Threshold on X-axis and EER on Y-axis
Correct answer: FAR on X-axis and FRR on Y-axis
A biometric ROC curve plots FAR on the X-axis against the True Acceptance Rate (1-FRR) on the Y-axis to show the accuracy trade-off across thresholds.
CBP CBP Biometric Performance Metrics and Testing 1
What does the False Acceptance Rate (FAR) measure in a biometric system?