collaborators

5 papers

cs.CL2025

The Surprising Effectiveness of Negative Reinforcement in LLM Reasoning

Xinyu Zhu, Mengzhou Xia, Zhepei Wei +3

Reinforcement learning with verifiable rewards (RLVR) is a promising approach for training language models (LMs) on reasoning tasks that elicit emergent long chains of thought (CoT…

cs.CL2025

BRIGHT: A Realistic and Challenging Benchmark for Reasoning-Intensive Retrieval

Hongjin Su, Howard Yen, Mengzhou Xia +12

Existing retrieval benchmarks primarily consist of information-seeking queries (e.g., aggregated questions from search engines) where keyword or semantic-based retrieval is usually…

cs.CL2024

SimPO: Simple Preference Optimization with a Reference-Free Reward

Yu Meng, Mengzhou Xia, Danqi Chen

Direct Preference Optimization (DPO) is a widely used offline preference optimization algorithm that reparameterizes reward functions in reinforcement learning from human feedback…

cs.LG2024

Assessing the Brittleness of Safety Alignment via Pruning and Low-Rank Modifications

Boyi Wei, Kaixuan Huang, Yangsibo Huang +6

Large language models (LLMs) show inherent brittleness in their safety mechanisms, as evidenced by their susceptibility to jailbreaking and even non-malicious fine-tuning. This stu…

cs.IR2024

LitSearch: A Retrieval Benchmark for Scientific Literature Search

Anirudh Ajith, Mengzhou Xia, Alexis Chevalier +3

Literature search questions, such as "Where can I find research on the evaluation of consistency in generated summaries?" pose significant challenges for modern search engines and…