arXiv Machine Learning

Gradient-Gated DPO: Stabilizing Preference Optimization in Language Models

arXiv Machine Learning
Aug 28

Disentangling Optimization Scale from Preference Scale in DPO

The paper investigates the Direct Preference Optimization (DPO) objective used for aligning language models, revealing that its coefficient β simultaneously controls both the inverse preference-noise scale and the optimization dynamics. This entanglement causes non‑monotonic policy deviation with respect to β and makes loss values incomparable across different β settings. The authors propose a centered‑softplus reformulation that decouples these effects, allowing independent tuning of the noise scale and learning‑rate, and provides a smooth β←0 limit that reduces to a linear preference‑margin objective.

By Ivan Kruzhilov
arXiv AI
2d ago

Gradient-Aligned Pair Selection for Personalized Preference Optimization

The paper introduces GAP-DPO, a method for personalizing large language models by selecting preference pairs based on gradient alignment with user utility. It formalizes personalized preference learning as a geometry‑aligned optimization problem, showing that off‑policy sampling can shift DPO updates from error correction to reinforcement when preference margins align with utility gradients. Experiments demonstrate that GAP‑DPO improves stylistic fidelity, preference alignment, and overall generation quality over standard DPO variants.

By Ruoming Jin, Xinyu Li, Hao Zhou, Jianfeng Zhu, Ruixin Guo, Feodor Dragan, Lei Xu, Haixun Wang, Yang Zhou
arXiv Machine Learning
Jun 25

Distribution Preference Optimization: A Fine-grained Perspective for LLM Unlearning

arXiv:2510. 04773v2 Announce Type: replace Abstract: As Large Language Models (LLMs) demonstrate remarkable capabilities learned from vast corpora, concerns regarding data privacy and safety are receiving increasing attention.

By Kai Qin, Jiaqi Wu, Jianxiang He, Haoyuan Sun, Yifei Zhao, Xu Wang, Bin Liang, Yongzhe Chang, Cheng Li, Tiantian Zhang, Houde Liu
arXiv Computation and Language
Sep 3

GroupDPO: Memory-Efficient Group-Wise Direct Preference Optimization

GroupDPO introduces a memory‑efficient approach to group‑wise direct preference optimization for aligning large language models. By using first‑order linearization with per‑response coefficients, the method decouples samples during backpropagation, dramatically reducing peak memory usage and enabling scalable training with larger groups. Experiments in both offline and online settings show that leveraging multiple responses consistently outperforms single‑pair training, and adding a negative log‑likelihood term on positive responses is essential for performance gains and training stability.

By Jixuan Leng, Si Si, Hsiang-Fu Yu, Vinod Raman, Inderjit S. Dhillon