arXiv AI

CroCo: Cross-Lingual Contrastive Preference Tuning on Self-Generations

CroCo introduces cross‑lingual contrastive preference tuning on self‑generations, extending prior English‑only methods to 14 high‑ and low‑resource languages. A reward model trained solely on English preferences, applied to a multilingual base, yields effective within‑language rankings and improves performance in both monolingual and multilingual settings without catastrophic forgetting. The approach requires on‑policy data; off‑policy responses and online preference optimization offer limited gains, yet on structured tasks CroCo matches or surpasses the base model in most languages, and on open‑ended generation it wins 28/30 judge evaluations across 15 languages.

arXiv AI
Aug 28

Language Chain in Alignment: Cross-lingual Ranking Preference Optimization

The paper introduces Cross‑lingual Ranking Preference Optimization (CRPO), a framework that uses high‑quality English preference data to improve alignment of large language models in other languages. CRPO builds a hierarchical structure over parallel preference pairs, jointly optimizing intra‑ and inter‑lingual preferences and providing a relative ranking signal beyond binary comparisons. Experiments on five languages show consistent gains in instruction‑following and knowledge utilization, with robust performance across different weighting schemes and improved reward margins and log‑probabilities of desirable responses.

By Seungyoon Lee, Minhyuk Kim, Jungseob Lee, Heuiseok Lim
arXiv AI
Jun 6

Macro: Enhancing Multilingual Counterfactual Explanations through Alignment-as-Preference Optimization

arXiv:2605. 11632v2 Announce Type: replace-cross Abstract: Self-generated counterfactual explanations (SCEs) are minimally modified inputs (minimality) generated by large language models (LLMs) that flip their own predictions (validity), offering a causally grounded approach to unraveling black-box LLM behavior.

By Yilong Wang, Qianli Wang, Bohao Chu, Yihong Liu, Jing Yang, Simon Ostermann
arXiv AI
Jun 2

S-SPPO: Semantic-Calibrated Self-Play Preference Optimization

arXiv:2606. 01561v1 Announce Type: new Abstract: Aligning Large Language Models (LLMs) with human preferences is often formulated via Direct Preference Optimization (DPO).

By Xiwen Chen, Wenhui Zhu, Jingjing Wang, Peijie Qiu, Zhipeng Wang, Huayu Li, ZhengXiao He, Xuanzhao Dong, Prayag Tiwari, Mingkun Xu, Yujian Xiong, Feng Luo, Abolfazl Razi, Brendan Hogan Rappazzo, Anderson Schneider, Yuriy Nevmyvaka