When Reflection Helps: Utility-Guided Advantage Rescaling for Efficient Reasoning

Jungyu Lee, Kunhui Lee, Dongwook Min, Jeonhwi Kang, Seung-Hoon Na


Abstract
Large reasoning models have recently demonstrated emergent “aha moments” that enable reflective reasoning. However, a non-trivial portion of reflective steps are “low-utility,” where reasoning errors are not corrected, or even correct reasoning trajectories are shifted toward incorrect ones. To address low-utility reflective continuation, this paper proposes RUAR, a utility-guided advantage rescaling method for reflective reasoning that estimates step-level utility from changes in correct-answer probability, without human process labels or a separately learned process reward model. RUAR augments outcome-supervised RL by rescaling the token-level advantages within each reflective reasoning step according to the estimated utility of the reflective continuation, rather than applying a uniform trajectory-level advantage across the reasoning trace. The utility is estimated through answer-forcing utility estimation, which measures how the model’s correct-answer probability changes before and after the reflective step by forcing answer generation from both reasoning states using answer-forcing prompts. Furthermore, RUAR introduces an overthinking-mitigating rescaling mechanism, where utility-guided rescaling is no longer applied from the earliest answer-ready reflection step onward. Experiments demonstrate that RUAR improves the accuracy–efficiency trade-off, substantially reducing generated token usage while often preserving or improving final-answer accuracy.
Anthology ID:
2026.findings-emnlp.1441
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
30739–30760
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1441/
DOI:
Bibkey:
Cite (ACL):
Jungyu Lee, Kunhui Lee, Dongwook Min, Jeonhwi Kang, and Seung-Hoon Na. 2026. When Reflection Helps: Utility-Guided Advantage Rescaling for Efficient Reasoning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 30739–30760, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Reflection Helps: Utility-Guided Advantage Rescaling for Efficient Reasoning (Lee et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1441.pdf