Triviality Corrected Endogenous Reward

Xinda Wang, Zhengxu Hou, Yangshijie Zhang, Yanbingren, Jialin Liu, ChenZhuo Zhao, Zhibo Yang, Bin-Bin Yang, Feng Xiao


Abstract
Reinforcement learning for open-ended text generation is constrained by the lack of verifiable rewards, necessitating reliance on judge models that require either annotated data or powerful closed-source models. Inspired by recent work on unsupervised reinforcement learning for mathematical reasoning using confidence-based endogenous rewards, we investigate whether this principle can be adapted to open-ended writing tasks. We find that directly applying confidence rewards leads to Triviality Bias: the policy collapses toward high-probability outputs, reducing diversity and meaningful content. We propose TCER (Triviality Corrected Endogenous Reward), which addresses this bias by rewarding the relative information gain between a specialist policy and a generalist reference policy, modulated by a probability-dependent correction mechanism. Across multiple writing benchmarks and model architectures, TCER achieves consistent improvements without external supervision. Furthermore, TCER also transfers effectively to mathematical reasoning, validating the generality of our approach across different generation tasks.
Anthology ID:
2026.acl-long.883
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
19334–19355
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.883/
DOI:
Bibkey:
Cite (ACL):
Xinda Wang, Zhengxu Hou, Yangshijie Zhang, Yanbingren, Jialin Liu, ChenZhuo Zhao, Zhibo Yang, Bin-Bin Yang, and Feng Xiao. 2026. Triviality Corrected Endogenous Reward. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 19334–19355, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Triviality Corrected Endogenous Reward (Wang et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.883.pdf
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