Mix decomposition · Simpson’s paradox
Operations performance
The headline trend reverses after controlling for work mix
-5.0 pp
Within-group effect
+16.0 pp
Mix effect
Comparing 2026-08-03 with 2026-08-10 across 2 matched workflow/market groups. Task-weighted accuracy changes +11.0 pp, but the fixed-mix change is -5.0 pp.
Accuracy must apply to the Tasks denominator. Rounded rates produce approximate error counts. These aggregated rows do not support individual-level significance tests or causal claims. No unmatched groups were silently excluded.