Twin-world counterfactuals isolate decision effects in agentic reinforcement learning

Sharing sampling noise between factual and alternative rollouts yields unbiased, lower-variance credit for each decision.

Top University
Zeropy Surio · Tobias Engel · Mei-Lin Chou · Anika Raman · Samuel Okafor

University of Sheffield · Carnegie Mellon University · University of Michigan

Research Digest··3 min read
The authors present TWICE, a method for credit assignment in agentic RL that generates counterfactual rollouts sharing the same Gumbel noise as the factual episode.

Reinforcement learning for search agents rewards only the final answer, making it hard to assign credit to individual decisions.

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Research Digest

Written by Alwyn Sage, research editor. Plate by Ollie Flash, picture desk.

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