activity
20242026
collaborators

20 papers

cs.CL2026

Why Generate a Click? Plug-in Decision Heads for Web Agents

Chengguang Gan, Yunhao Liang, Hanjun Wei +3

Web agents built on vision language models decide every action by generating text such as click(12), although most of that text encodes a choice among a few action types and a few…

cs.SE2026

LLM-Based Test Generation: Information Sources, Generation Strategies, and Quality Evidence

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Large language models are increasingly used to generate test scenarios, executable test suites, assertions, interaction sequences, and fuzzing infrastructure. These artifacts serve…

cs.CL2026

Certified Selective Automation of LLM Agent Evaluation

Chengguang Gan, Yunhao Liang, Qinghao Zhang +1

Evaluating LLM agents still ends with a human reading trajectories, because automatic judges carry no guarantee on how often they are wrong. We ask the operational question: what f…

cs.CL2026

Guides That Cause Actions: An Offline Study of Guide-Action Mutual Reinforcement in Multimodal Web Agents

Chengguang Gan, Yunhao Liang, QingHao Zhang +1

Web agents are usually evaluated in live environments, where environment state and judge models drift between runs, so the same checkpoint rarely reproduces the same score, making…

cs.SE2026

Test-Driven Approaches to Software Engineering with Large Language Models: A Survey of Phases, Tasks, and Agent Skills

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Tests increasingly participate in the decisions made by large language models and software engineering agents. They specify intended behavior, guide program construction and repair…

cs.SE2026

Correct Tests Are Not Enough: Measuring and Training Oracle Conversion in Specification-Based Test Generation

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Generating tests from a natural-language specification requires both an input that exposes faulty behavior and a correct expected output. These requirements need not improve togeth…

cs.CL2026

How Output Format Confounds Data Quality and Capability in Instruction Tuning

Chengguang Gan, Hanjun Wei, Yunhao Liang +3

Instruction-tuning data are judged by quality metrics, and tuned models are judged by benchmarks, but both judgments pass through an output interface: the surface format in which a…

cs.CL2026

Joint Training Is Not Enough: Conditioned Cross-Granularity Training for Multimodal Document Understanding

Chengguang Gan, Yunhao Liang, Hanjun Wei +2

The Mutual Reinforcement Effect (MRE) asks whether a fine, span-level and a coarse, document-level task help each other when one model handles both. We test it in multimodal docume…

cs.SE2026

Auditing and Decomposing Feedback-Driven Evolution in LLM Test Generation under the Oracle Problem

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Execution feedback is often treated as a self-verifying signal for improving LLM-generated tests. However, when generated inputs are executed on a single accepted program and its o…

cs.SE2026

Security Tests as Executable Specifications for LLM Code Generation: Benefits, Trade-offs, and Coverage Limits

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Large language models (LLMs) can generate functionally useful code that remains vulnerable, while security-focused interventions may break intended behavior. We investigate securit…

cs.AI2026

MAG: A Web-Agent Benchmark and Harness for Multimodal Action and Guide Generation

Chengguang Gan, Hanjun Wei, Yunhao Liang +3

Digital Adoption Platforms (DAPs) are embedded overlays widely used on web systems to guide users through operations inside a page, helping them get started with unfamiliar interfa…

cs.AI2026

A Learning-Rate-Gated Failure of GRPO in a Small Language and Vision-Language Model Web Agent: A Controlled Null and Its Mechanism

Chengguang Gan, Zhixi Cai, Yunhao Liang +3

Reinforcement learning with verifiable rewards, and Group Relative Policy Optimization (GRPO) in particular, is now run routinely on a supervised checkpoint in the hope of producin…

cs.SE2026

Do Code Language Models Follow Tests? Paired Interventions on Program Behavior

Yunhao Liang, Chengguang Gan, Ruixuan Ying +3

Visible tests specify concrete program behavior, but an improvement in benchmark accuracy does not establish that a model follows the rule expressed by those tests. We study test u…

cs.SE2026

Scaling Test-Driven Code Generation from Functions to Classes: An Empirical Study

Yunhao Liang, Ruixuan Ying, Shiwen Ni +1

Test-driven development (TDD) has been adopted to improve Large Language Model (LLM)-based code generation by using tests as executable specifications. However, existing TDD-style…

cs.CL2026

GuideWeb: A Benchmark for Automatic In-App Guide Generation on Real-World Web UIs

Chengguang Gan, Yoshihiro Tsujii, Yunhao Liang +3

Digital Adoption Platform (DAP) provide web-based overlays that deliver operation guidance and contextual hints to help users navigate complex websites. Although modern DAP tools e…

cs.LG2025

Earley-Driven Dynamic Pruning for Efficient Structured Decoding

Xintong Sun, Chi Wei, Minghao Tian +1

Large Language Models (LLMs) have shown remarkable capabilities, yet ensuring their outputs conform to strict structural or grammatical constraints remains challenging, which is cr…

cs.CV2025

ScaleLong: A Multi-Timescale Benchmark for Long Video Understanding

David Ma, Huaqing Yuan, Xingjian Wang +16

Although long-video understanding demands that models capture hierarchical temporal information -- from clip (seconds) and shot (tens of seconds) to event (minutes) and story (hour…

cs.CV2025

IV-Bench: A Benchmark for Image-Grounded Video Perception and Reasoning in Multimodal LLMs

David Ma, Yuanxing Zhang, Jincheng Ren +17

Existing evaluation frameworks for Multimodal Large Language Models (MLLMs) primarily focus on image reasoning or general video understanding tasks, largely overlooking the signifi…

cs.CL2025

M-MRE: Extending the Mutual Reinforcement Effect to Multimodal Information Extraction

Chengguang Gan, Zhixi Cai, Yanbin Wei +3

Mutual Reinforcement Effect (MRE) is an emerging subfield at the intersection of information extraction and model interpretability. MRE aims to leverage the mutual understanding be…

cs.CL2024

A Multilingual Dataset and Empirical Validation for the Mutual Reinforcement Effect in Information Extraction

Chengguang Gan, Sunbowen Lee, Qingyu Yin +9

The Mutual Reinforcement Effect (MRE) describes a phenomenon in information extraction where word-level and sentence-level tasks can mutually improve each other when jointly modele…