arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2602.01685cs.LGcs.AI
收藏

语义感知的Wasserstein策略正则化用于大语言模型对齐

Semantic-aware Wasserstein Policy Regularization for Large Language Model Alignment

KAIST(韩国科学技术院);UNIST(蔚山科学技术院)

Byeonghu Na, Hyungho Na, Yeongmin Kim, Suhyeon Jo, HeeSun Bae, Mina Kang, Il-Chul Moon

AI总结:

本文提出Wasserstein策略正则化方法,通过语义感知的Wasserstein距离改进大语言模型对齐效果,实验表明其优于传统KL散度方法。

摘要:

大语言模型(LLMs)通常通过人类反馈强化学习(RLHF)与人类偏好对齐。在该方法中,LLM策略通常通过奖励最大化与参考策略的KL散度正则化进行优化。然而,KL及其f-散度变体仅比较相同索引的令牌概率,无法捕捉语义相似性。我们提出Wasserstein策略正则化(WPR),一种基于熵正则化的Wasserstein距离的语义感知正则化方法,用于RLHF框架。距离的对偶形式将正则化表达为通过最优对偶变量施加于奖励的惩罚项,从而得到与标准RL算法兼容的可处理目标。实验表明,我们的方法优于基于KL和f-散度的基线方法,证明了语义感知策略距离对对齐的益处。我们的代码可在https://github.com/aailab-kaist/WPR上获取。

英文摘要:

Large language models (LLMs) are commonly aligned with human preferences using reinforcement learning from human feedback (RLHF). In this method, LLM policies are generally optimized through reward maximization with Kullback-Leibler (KL) divergence regularization of the reference policy. However, KL and its $f$-divergence variants only compare token probabilities at identical indices, failing to capture semantic similarity. We propose Wasserstein Policy Regularization (WPR), a semantic-aware regularization for the RLHF framework based on the entropy-regularized Wasserstein distance, which incorporates the geometry of the token space. The dual formulation of the distance expresses the regularization as penalty terms applied to the reward via optimal dual variables, which yield a tractable objective compatible with standard RL algorithms. Empirically, our method outperforms KL- and $f$-divergence-based baselines, demonstrating the benefits of semantic-aware policy distances for alignment. Our code is available at https://github.com/aailab-kaist/WPR.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑