MulFeRL: Enhancing Reinforcement Learning with Verbal Feedback in a Multi-turn Loop

Xuancheng Li, Haitao Li, Yujia Zhou, Yiqun Liu, Min Zhang, Qingyao Ai


Abstract
Reinforcement Learning with Verifiable Rewards (RLVR) is widely used to improve reasoning across domains, but outcome-only scalar rewards are often sparse and uninformative, especially for failed samples, where they indicate only failure without explaining why the reasoning breaks down. In this paper, we leverage richer verbal feedback to guide RLVR on failed samples and convert feedback-induced progress into trainable learning signals. We propose MulFeRL (Multi-turn Feedback-guided Reinforcement Learning), a multi-turn, event-triggered RLVR framework that combines progress induction for feedback-guided regeneration of failed samples, progress credit assignment for learning from verifier-confirmed progress, and structured feedback injection for integrating feedback into the model’s reasoning process. Trained on sampled OpenR1-Math, MulFeRL outperforms supervised, self-distillation-based, and RLVR baselines in-domain and shows strong out-of-domain generalization. [We release our code at <https://anonymous.4open.science/r/MulFeRL>.]
Anthology ID:
2026.emnlp-main.2116
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
48119–48153
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2116/
DOI:
Bibkey:
Cite (ACL):
Xuancheng Li, Haitao Li, Yujia Zhou, Yiqun Liu, Min Zhang, and Qingyao Ai. 2026. MulFeRL: Enhancing Reinforcement Learning with Verbal Feedback in a Multi-turn Loop. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 48119–48153, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
MulFeRL: Enhancing Reinforcement Learning with Verbal Feedback in a Multi-turn Loop (Li et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2116.pdf