Description
Return standardized and min-max score values.
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 standardized and min-max score values.
When to use this tool
Use Biometric Score Normalization One Reference when checking the stated biometric score, threshold, reporting precision or error-denominator convention.
How to use the tool and how it works
- Enter score, mean, sd, referenceMinimum, referenceMaximum. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read z, minMax. Use the output convention below.
Return standardized and min-max score values. Require sd > 0 and referenceMaximum > referenceMinimum; z = (score-mean)/sd, minMax = (score-min)/(max-min).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| score | Score | Required. Finite number. |
| mean | Mean | Required. Finite number. |
| sd | Sd | Required. Finite number; strictly above 0. |
| referenceMinimum | Reference Minimum | Required. Finite number. |
| referenceMaximum | Reference Maximum | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| z | Z | Required. Finite number. |
| minMax | Unclamped (score-minimum)/(maximum-minimum), not a match probability. | Required. Finite number. |
{
"input": {
"score": 70,
"mean": 50,
"sd": 10,
"referenceMinimum": 0,
"referenceMaximum": 100
},
"output": {
"z": 2,
"minMax": 0.7
}
}Limitations and assumptions
- Parameters are supplied and outputs are not clamped; neither calibrated match probability nor population suitability 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 Score Tie Quantum
Return floor-quantized score bins and their equality.
- Biometric Threshold Quantization Tie Interval
Return a score-precision envelope and threshold overlap.