I/O Analytics
Adverse impact analysis
The 4/5ths rule
Under the Uniform Guidelines on Employee Selection Procedures (29 C.F.R. § 1607), an adverse impact finding arises when the selection rate for a protected group is less than four-fifths (80%) of the rate for the group with the highest selection rate. Employers are expected to monitor this ratio for any procedure — including personality assessments and cognitive batteries — used in hiring decisions.
The formula:
Impact ratio = (selection rate, protected group) ÷ (selection rate, majority group) If impact ratio < 0.80 → potential adverse impact flagged
Illustrative example
| Group | Candidates evaluated | Meet cutoff (≥ 60%) | Selection rate | Impact ratio | Result |
|---|---|---|---|---|---|
| Group A | 60 | 42 | 70.0% | — | (reference) |
| Group B | 55 | 28 | 50.9% | 0.727 | Below 4/5ths |
In this example, 10 additional Group B hires would be needed to reach the 80% threshold. The platform shows this alongside the cutoff simulation so employers can evaluate score-cut alternatives before finalising a selection decision.
What the toolset provides
- Group tagging — label each candidate as Group A, Group B, or Untagged directly from your battery console.
- Cutoff-score simulator — choose any facet or domain column and a pass-mark threshold; the platform instantly computes the 4/5ths ratio, flags potential adverse impact, and estimates the additional hires needed to comply.
- UGESP compliance PDF — a downloadable report containing the adverse impact table, per-instrument reliability and validity evidence from published sources, and a Selection Procedure Documentation section formatted for UGESP record-keeping.
Request access
To enable the adverse impact toolset for your organisation, send a brief note below. Include your battery name or role if you have one in mind.