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Many A/B Tests Shared the Same Reward

A tree-coupled design preserved each policy's standalone trajectory law while reusing matched feedback across comparisons.

Published Updated Story ID: mp-2026-08-16-010
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Summary

A tree-coupled design preserved each policy's standalone trajectory law while reusing matched feedback across comparisons.

Directly comparing J adaptive policies for T rounds consumes JT reward-bearing interactions. The proposed exact coupling connects policy histories with a predictable tree, shares one reward within matched components and retains each policy's finite-horizon law. Its query count becomes T plus cumulative edge mismatches and can approach T rather than JT when policies converge. Experiments on reward models, language-model evaluation and adaptive search reported a better cost-precision frontier; practical gains depend on how closely the policies' actions can be coupled.

Why it matters

A tree-coupled design preserved each policy's standalone trajectory law while reusing matched feedback across comparisons.

Limits and context

No additional limitation was separately recorded.

Key claims

  1. A tree-coupled design preserved each policy's standalone trajectory law while reusing matched feedback across comparisons.

    Evidence: source-2026-08-16-010

Sources

  1. arXiv preprint 2608.12831arXiv · primary research

Corrections

No corrections have been recorded for this story.