Implementation Kit
AI Fairness Metric Selection Worksheet and Test Plan
The step before testing: choosing the fairness definition that fits your use case, since you cannot satisfy all of them at once. A selection worksheet, an intersectional test plan, and a re-test schedule. Pair it with the Bias Testing Kit for the mechanics.
Who this is for: The model owner and legal partner deciding what "fair" means for this specific system before any metric is computed.
1. Fairness definition selection worksheet
SpreadsheetWalks from use-case properties to a recommended fairness metric, with the trade-off made explicit.
Template
| Question | Answer | Implication |
|---|---|---|
| Is the decision allocating an opportunity (hiring, credit, housing) or a burden (fraud flag, audit, moderation)? | Opportunity: watch false negatives. Burden: watch false positives. | |
| Are base rates genuinely equal across groups, or is that assumption contested? | If base rates differ and are legitimate, demographic parity may be the wrong target | |
| Is there a legally recognised protected class and a disparate-impact standard that applies? | The four-fifths rule becomes a hard screen, not just a diagnostic | |
| Do individuals reasonably expect similar people to be treated similarly? | Adds an individual-fairness check on top of a group metric | |
| Can we lawfully use group-aware post-processing in this jurisdiction? | Constrains which remediations are available | |
| Recommended primary metric: | e.g. equalized odds, demographic parity, calibration within groups | |
| Secondary checks: | ||
| Accepted trade-off: | which fairness property we are knowingly not optimising, and why |
Worked example
| Question | Answer | Implication |
|---|---|---|
| Opportunity or burden? | Opportunity (hiring screen) | Prioritise false-negative parity |
| Base rates equal? | Contested; historical hiring skew present | Demographic parity risky as a sole target |
| Protected class + disparate-impact standard? | Yes (sex, race; Title VII, NYC LL144) | Four-fifths is a hard screen |
| Individual-fairness expectation? | Yes | Add a "similar applicants, similar scores" spot check |
| Group-aware post-processing lawful? | Restricted for hiring in the US | Prefer pre-processing and feature fixes |
| Recommended primary metric | Equalized odds (focus on FNR parity) | |
| Secondary checks | Four-fifths selection-rate screen; score-distribution comparison | |
| Accepted trade-off | Not enforcing strict demographic parity; documented with Legal |
Acceptance criteria
- ✓The primary fairness metric is chosen and written down before any results are seen.
- ✓The worksheet names the fairness property being traded away and why.
- ✓Legal has reviewed the choice where a protected class is involved.
2. Intersectional test plan
SpreadsheetWhich group combinations to test, and which are too small to be reliable.
Template
| Attribute combination | Estimated N in eval set | Test? | If not, why |
|---|---|---|---|
| sex | Yes | ||
| race/ethnicity | Yes | ||
| age band | Yes | ||
| sex x race/ethnicity | Yes / No | sample size | |
| sex x age band | Yes / No | ||
| race/ethnicity x age band | Yes / No |
Worked example
| Combination | N in eval set | Test? | Note |
|---|---|---|---|
| sex | 38,000 | Yes | |
| race/ethnicity | 38,000 | Yes | |
| age band | 38,000 | Yes | |
| sex x race/ethnicity | ~1,100 smallest cell | Yes | report with confidence intervals |
| sex x age band | ~2,400 smallest cell | Yes | |
| race/ethnicity x age band | ~140 smallest cell | No | cell too small; monitor in production aggregate |
Acceptance criteria
- ✓Single attributes are always tested; intersections are tested where the smallest cell supports it.
- ✓Untested combinations are named with the reason, and picked up in production monitoring.
- ✓Results for small cells are reported with uncertainty, not as point estimates.
3. Fairness re-test schedule
SpreadsheetWhen the chosen metrics are recomputed, tied to the model review cycle.
Template
| System | Primary metric | Routine cadence | Trigger events | Owner | Next run |
|---|---|---|---|---|---|
| <system> | <metric> | monthly / quarterly | model change; data refresh; population shift; incident | <name> | YYYY-MM-DD |
Worked example
| System | Primary metric | Routine cadence | Trigger events | Owner | Next run |
|---|---|---|---|---|---|
| resume-screener | equalized odds (FNR parity) + four-fifths screen | monthly | any model version; quarterly data refresh; complaint | DS team | 2026-10-01 |
Acceptance criteria
- ✓Re-test cadence matches the model review cadence at minimum.
- ✓Trigger events force an out-of-cycle run.
- ✓Results land in the bias testing audit trail.
Governance controls this kit produces evidence for
Completing the artifacts above gives you a head start on the evidence requirements for these controls.
The chosen metric plus the re-test schedule define what fairness monitoring runs and when.
The worksheet ties the fairness approach to the system's risk classification and use-case type.
The selected fairness definition is the fairness axis of a benchmark-aligned evaluation framework.
This kit backs one playbook. Read the full guidance for the reasoning behind each artifact.
Decide what to implement next
Assess your governance gaps, then create an action plan with owners and target dates. Build and export without an account; sign in when you want to save your plan.
Start the AI governance assessment →