Adaptive Preference Optimization with Uncertainty-aware Utility Anchor

Xiaobo Wang, Zixia Jia, Jiaqi Li, Qi Liu, Zilong Zheng


Abstract
Offline preference optimization methods are efficient for large language models (LLMs) alignment. Direct Preference optimization (DPO)-like learning, one of the most popular approaches, stands out for its efficiency in reward modeling. However, these methods typically follow the convention to use Bradley-Terry (BT) reward modeling that faces several critical assumptions, including the requirement for pairwise training data, model distribution shifting, human rationality assumption, etc. To address these limitations, we propose a general framework for offline preference optimization methods, Adaptive Preference Optimization with Utility Anchor (UAPO), which introduces an anchoring function to estimate the uncertainties brought from preference data annotation. Our method enables training even in scenarios where the data is unpaired, significantly enhancing data utilization efficiency. Moreover, the anchor design makes UAPO more robust in the training process. Experimental results demonstrate that UAPO achieves competitive outcomes without the strict dependency on data pairing, paving the way for more flexible and effective preference optimization methods.
Anthology ID:
2025.findings-emnlp.1046
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
19204–19225
Language:
URL:
https://preview.aclanthology.org/ingest-luhme/2025.findings-emnlp.1046/
DOI:
10.18653/v1/2025.findings-emnlp.1046
Bibkey:
Cite (ACL):
Xiaobo Wang, Zixia Jia, Jiaqi Li, Qi Liu, and Zilong Zheng. 2025. Adaptive Preference Optimization with Uncertainty-aware Utility Anchor. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 19204–19225, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Adaptive Preference Optimization with Uncertainty-aware Utility Anchor (Wang et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/ingest-luhme/2025.findings-emnlp.1046.pdf
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