Entropy-Aware Reshaping of Reinforcement Signals for Multi-Answer Reasoning

Zhi Li, Huidan Xu, Zhen Hu, Yali Du, Ying Liu


Abstract
Reinforcement learning with verifiable rewards (RLVR) is a standard post-training paradigm for large language models (LLMs), typically relying on group-wise reward and advantage normalization for stability. In set-valued multi-answer tasks, where multiple outputs may be simultaneously correct, this normalization can over-amplify a small number of early high-reward samples, suppressing learning signals from other valid generations and leading to overly concentrated updates. We propose Entropy-Aware Reshaping of Reinforcement Signals (EARS), a framework that reshapes how learning signals are normalized and aggregated. EARS uses token-level predictive entropy as an uncertainty cue to compute entropy-weighted reward statistics for advantage normalization, encouraging broader exploration and more balanced learning-signal allocation early in training. An adaptive decay schedule then anneals uncertainty-aware reweighting back to standard group normalization to ensure stable convergence. EARS further incorporates a correctness-gated multi-head process reward that provides auxiliary supervision on reasoning traces while remaining aligned with verifiable correctness. Experiments on MCTACO and MMLU-Multi using Qwen2.5-7B and Llama-3.1-8B-Instruct demonstrate consistent improvements in exact-set accuracy, training stability, and cross-dataset transfer performance on set-valued multi-answer reasoning.
Anthology ID:
2026.findings-acl.2001
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
40255–40268
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2001/
DOI:
Bibkey:
Cite (ACL):
Zhi Li, Huidan Xu, Zhen Hu, Yali Du, and Ying Liu. 2026. Entropy-Aware Reshaping of Reinforcement Signals for Multi-Answer Reasoning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 40255–40268, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Entropy-Aware Reshaping of Reinforcement Signals for Multi-Answer Reasoning (Li et al., Findings 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2001.pdf
Checklist:
 2026.findings-acl.2001.checklist.pdf