Gradient-Adaptive Policy Optimization: Towards Multi-Objective Alignment of Large Language Models
Chengao Li, Hanyu Zhang, Yunkun Xu, Hongyan Xue, Xiang Ao, Qing He
Abstract
Reinforcement Learning from Human Feedback (RLHF) has emerged as a powerful technique for aligning large language models (LLMs) with human preferences. However, effectively aligning LLMs with diverse human preferences remains a significant challenge, particularly when they are conflict. To address this issue, we frame human value alignment as a multi-objective optimization problem, aiming to maximize a set of potentially conflicting objectives. We introduce Gradient-Adaptive Policy Optimization (GAPO), a novel fine-tuning paradigm that employs multiple-gradient descent to align LLMs with diverse preference distributions. GAPO adaptively rescales the gradients for each objective to determine an update direction that optimally balances the trade-offs between objectives. Additionally, we introduce P-GAPO, which incorporates user preferences across different objectives and achieves Pareto solutions that better align with the user’s specific needs.- Anthology ID:
- 2025.acl-long.549
- Volume:
- Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
- Month:
- July
- Year:
- 2025
- Address:
- Vienna, Austria
- Editors:
- Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
- Venue:
- ACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 11214–11232
- Language:
- URL:
- https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.549/
- DOI:
- Cite (ACL):
- Chengao Li, Hanyu Zhang, Yunkun Xu, Hongyan Xue, Xiang Ao, and Qing He. 2025. Gradient-Adaptive Policy Optimization: Towards Multi-Objective Alignment of Large Language Models. In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 11214–11232, Vienna, Austria. Association for Computational Linguistics.
- Cite (Informal):
- Gradient-Adaptive Policy Optimization: Towards Multi-Objective Alignment of Large Language Models (Li et al., ACL 2025)
- PDF:
- https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.549.pdf