arXiv AI

TPO: Tri-level Distributionally Robust Learning for OOD Direct Preference Optimization

arXiv Machine Learning
Sep 29

Learning Where It Matters: Geometric Anchoring for Robust Preference Alignment

The paper introduces Geometric Anchor Preference Optimization (GAPO), a method that replaces the static reference policy in Direct Preference Optimization with a dynamic, geometry-aware anchor—a small adversarial perturbation of the current policy. GAPO uses this anchor to adaptively reweight preference pairs based on local sensitivity, and defines an Anchor Gap that approximates worst‑case local margin degradation. Experiments show that GAPO improves robustness to noisy supervision while matching or surpassing existing LLM alignment and reasoning benchmarks.

By Youngjae Cho, Jongsuk Kim, Ji-Hoon Kim
arXiv Machine Learning
Oct 15

Unification and Optimization of Robust Supervised Learning

arXiv:2605.28165v2 Announce Type: replace Abstract: Robust learning methods such as distributionally robust optimization, vicinal risk minimization, Mixup, and label smoothing address different sourc...

By Jonas Hanselle, Valentin Margraf, Clemens Damke, Eyke H\"ullermeier
arXiv AI
Oct 2

Robust Nash Alignment under Preference Uncertainty

Robust Nash Alignment introduces a game-theoretic framework that seeks a policy with a high worst-case win rate against both an adversarial competitor and any preference kernel within an ambiguity set around a nominal preference. The authors propose a four-player primal-dual proxy game and an optimistic mirror descent-ascent algorithm to efficiently optimize this robust objective, proving convergence guarantees and demonstrating improved performance in controlled tabular games and LLM alignment experiments.

By Shihab Ahmed, Debamita Ghosh, David Tang, Yudan Wang, Alvaro Velasquez, Yue Wang
arXiv Machine Learning
2d ago

Doubly Robust Distributionally Robust Offline Contextual Pricing

The paper introduces a doubly robust framework for distributionally robust offline contextual pricing, addressing challenges of distributional shifts and continuous actions. It proposes a localized DR estimator that is computationally efficient and semiparametrically optimal, and a learning algorithm that exploits demand noise smoothness to achieve finite‑sample regret bounds of τ^{-σ/(2σ+1)} for smoothness orders s=1,2. Experiments across varying distribution shifts demonstrate the effectiveness of the proposed methods.

By Min Xu, Xinyi Yin, Yunfan Zhang, Yuxuan Han, Houcai Shen, Caihua Chen
arXiv Machine Learning
Oct 9

Calibrating Ambiguity Set via Diagnostic Transport for Distributionally Robust Optimization

The paper introduces Diagnostic-Transport DRO (DT‑DRO), a method that calibrates the geometry of the ambiguity set in distributionally robust optimization using held‑out data. By applying the conditional probability integral transform to detect systematic probability misallocation, DT‑DRO adjusts both the ambiguity‑set center and ground cost through an outcome‑level transport, yielding a computationally tractable dual reformulation. The authors provide theoretical guarantees on ambiguity radii and decision‑risk bounds that improve as estimation errors shrink, and demonstrate that DT‑DRO can remove the robustness floor caused by model misspecification in synthetic and power‑outage experiments.

By Wenbin Zhou, Elizabeth Cucuzzella, Shixiang Zhu