collaborators

11 papers

cs.AI2026

When Many Answers Are Valid, Voting Fails: Symbolic Verification for Best-of-K Causal Reasoning in LLMs

Omatharv Bharat Vaidya, Connor Thomas Jerzak, Zayne Rea Sprague +2

Self-consistency assumes the most frequent answer among sampled reasoning traces is the most reliable, but this can fail in causal reasoning: samples often repeat the same confound…

cs.CL2026

Visually Grounded Self-Reflection for Vision-Language Models via Reinforcement Learning

Liyan Tang, Fangcong Yin, Greg Durrett

Large vision-language models can reason over multimodal inputs by generating textual chains of thought (CoT). A key capability exhibited in CoT reasoning is self-reflection: revisi…

cs.CL2026

Randomized YaRN Improves Length Generalization for Long-Context Reasoning

Manas Mehta, Fangcong Yin, Greg Durrett

Large language models (LLMs) are typically pretrained on short sequences and then extended to work on longer sequences with additional training. However, such LLMs still struggle t…

cs.LG2026

Detecting and Suppressing Reward Hacking with Gradient Fingerprints

Songtao Wang, Quang Hieu Pham, Fangcong Yin +4

Reinforcement learning with verifiable rewards (RLVR) typically optimizes for outcome rewards without imposing constraints on intermediate reasoning. This leaves training susceptib…

cs.CL2026

ChartMuseum: Testing Visual Reasoning Capabilities of Large Vision-Language Models

Liyan Tang, Grace Kim, Xinyu Zhao +12

Chart understanding presents a unique challenge for large vision-language models (LVLMs), as it requires the integration of sophisticated textual and visual reasoning capabilities.…

cs.CL2025

Query-Focused Retrieval Heads Improve Long-Context Reasoning and Re-ranking

Wuwei Zhang, Fangcong Yin, Howard Yen +2

Recent work has identified retrieval heads, a subset of attention heads responsible for retrieving salient information in long-context language models (LMs), as measured by their c…