Ethics
Mar 30, 2026 · 7 min read
Adverse impact occurs when a selection process disproportionately screens out members of a protected class. The classic 4/5ths (80%) rule from the Uniform Guidelines on Employee Selection Procedures compares the selection rate of each group against the highest-selected group; a ratio below 0.8 is treated as a trigger for investigation.
It is a screening heuristic, not a legal standard, and it is unstable in small samples — a single decision can swing the ratio across the threshold in a pipeline of forty. Report it with the sample size and a significance test, or you will chase noise.
TalentSpark's DEI dashboard surfaces this calculation in real time so you can catch drift before it becomes a legal exposure — and before you've made a year of decisions on a biased pipeline.