Description
Return acquisition-failure rate and usable-acquisition count.
Biometric scores depend on matcher version, score direction, acquisition handling and an explicit operating threshold. Score transformations and observed error fractions are different from identity verification; equality, quantization and excluded attempts can change the local reported result.
Return acquisition-failure rate and usable-acquisition count.
When to use this tool
Use Biometric Failure Acquisition Share when checking the stated biometric score, threshold, reporting precision or error-denominator convention.
How to use the tool and how it works
- Enter attempts, failedAcquisitions, excludedAttempts, excludeFromBase. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read denominator, rate, usableAcquisitions. Use the output convention below.
Return acquisition-failure rate and usable-acquisition count. Require positive whole attempts, excludedAttempts < attempts and failures within unexcluded attempts; denominator subtracts excluded only under policy, usable always subtracts both excluded and failed.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| attempts | Attempts | Required. Safe integer; minimum 1. |
| failedAcquisitions | Failed Acquisitions | Required. Safe integer; minimum 0. |
| excludedAttempts | Excluded Attempts | Required. Safe integer; minimum 0. |
| excludeFromBase | Exclude From Base | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| denominator | Denominator | Required. Safe integer. |
| rate | Rate | Required. Finite number. |
| usableAcquisitions | Usable Acquisitions | Required. Safe integer. |
{
"input": {
"attempts": 100,
"failedAcquisitions": 5,
"excludedAttempts": 10,
"excludeFromBase": true
},
"output": {
"denominator": 90,
"rate": 0.05555555555555555,
"usableAcquisitions": 85
}
}Limitations and assumptions
- The exclusions and failure assertions are supplied; no capture is processed and no security or fairness outcome is established.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Evaluate a validated matcher on relevant complete data with explicit acquisition/exclusion and threshold policies; assess uncertainty, privacy and fairness independently.
References
Similar or alternative tools
- Biometric False Match Count Denominator
Return false-match rate under an excluded-count denominator policy.
- Biometric Detection Error One Operating Point
Return false-accept/reject rates and expected error cost at one point.