Sample size (or number of clusters) by treatment arms
Assignment was hierarchical, so the 21 final arms were not designed to have equal sample sizes. Of approximately 1,000,000 planned randomization units, the four broad conditions were expected to receive approximately 250,000 units each:
No prediction: approximately 250,000 units in one arm.
Traditional prediction model: approximately 250,000 units, divided equally across four precision arms, or approximately 62,500 units per arm.
AI maximum-probability rule: approximately 250,000 units, divided equally across two route-disclosure conditions and four precision levels, or approximately 31,250 units per arm across eight arms.
AI fastest-time rule: approximately 250,000 units, divided equally across two route-disclosure conditions and four precision levels, or approximately 31,250 units per arm across eight arms.
Actual realized sample sizes could differ because of platform traffic, logging availability, and the timing of eligible shipment queries.