Weinan Zhang
Other people with similar names: Weinan Zhang (University College London)
Unverified author pages with similar names: Weinan Zhang
2026
Exploring and Distilling Multi-Dimensional Clues for Interpretable Social Bot Detection
Yi Han | Haiqi Lu | Lizi Liao | Shuhan Zhou | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Yi Han | Haiqi Lu | Lizi Liao | Shuhan Zhou | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Social bot accounts have long been disseminating disinformation and engaging in malicious activities on social media platforms. Detecting these social bots has become a critical and urgent task, essential for maintaining a healthy online ecosystem. Existing social bot detection research usually provides detection results directly without corresponding supportive explanations, making it difficult to assess the extent to which such predictions are trustworthy. This is a key concern for online moderation. In this work, we explore the detection interpretation and summarize a four-dimensional clue framework from individual and social perspectives. We propose CDRBot, which primarily employs outcome-reward reinforcement learning to train inspectors to generate faithful, grounded, and readable clues from the *User Information*, *Semantic Features*, *Interactive Situation*, and *Behavioral Pattern*. These clues are then integrated to make final predictions. Experimental results demonstrate that our approach outperforms other baselines in detection performance. The generated clues are faithful, grounded, and readable, and can significantly enhance the performance of large language models in social bot detection.
FAER: Benchmarking VLMs for Failure-Aware Embodied Reasoning
Hao Song | Kaifeng Liu | Yuanxing Liu | Xiang Tian | Xuesong Wang | Chen Yifan | Weinan Zhang | Ting Liu
Findings of the Association for Computational Linguistics: ACL 2026
Hao Song | Kaifeng Liu | Yuanxing Liu | Xiang Tian | Xuesong Wang | Chen Yifan | Weinan Zhang | Ting Liu
Findings of the Association for Computational Linguistics: ACL 2026
Failures are inevitable when embodied agents execute complex tasks. Visual-language models (VLMs) serve as the core component of embodied agents in perceiving the environment and making decisions. Assessing the capabilities of VLMs in detecting and reasoning about failures has become increasingly important. Previous work primarily considered low-level manipulation failures (e.g., 3cm grasp offsets), neglecting high-level failures arising during long-horizon task execution (e.g., object-dropping failure in the “clean room” task) by embodied agents. In this paper, we propose FAER, a failure-aware benchmark aiming to evaluate the performance of VLMs in terms of failure detection, failure categorization, failure description, and failure correction in long-horizon tasks. FAER comprises 3,323 episodes, spanning 3 scenes, 65 tasks, and 83 objects. We assess the performance of 16 widely utilized VLMs and 4 LLMs for FAER tasks. Experimental results show that nearly all VLMs, even GPT-4o, exhibit limited performance in failure detection with a high false negative rate, meaning that they tend to ignore abnormal events, revealing notable gaps in current models’ capacity to effectively handle failures.
2025
Stimulate the Critical Thinking of LLMs via Debiasing Discussion
Ruiyu Xiao | Lei Wu | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Ruiyu Xiao | Lei Wu | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) often succumb to users’ viewpoints when faced with conflicting perspectives. We identify two key biases underlying this issue : stance homogeneity bias and human preference bias. To address these biases, we propose a novel two-stage training framework: Multi-stance Discussion Sampling and Truth Alignment Training (MDTA). First, we introduce an equal multi-stance discussion framework to automatically generate multi-model discussion datasets. Based on this framework, we construct the first and largest multi-model fair discussion dataset named Eq-Discussion for supervised fine-tuning, reducing stance homogeneity bias. Second, we optimize Reinforcement Learning from Human Feedback (RLHF) to align with discussion correctness, mitigating human preference bias. Extensive experimental results demonstrate that MDTA effectively reduces both biases and significantly enhances the performance of LLMs across a variety of downstream tasks, including reading comprehension, logical reasoning, and social question answering. Furthermore, we observe that MDTA improves the generalization capabilities of LLMs, leading to substantial performance improvements in non-discussion scenarios and on out-of-domain datasets.
Nullspace Disentanglement for Red Teaming Language Models
Yi Han | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Yi Han | Yuanxing Liu | Weinan Zhang | Ting Liu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
With the widespread deployment of generative language models, concerns about safety issues have continuously grown. High-quality fine-tuning data generated from red teaming plays a crucial role in the model’s safety. Recently, automated red teaming approaches have been proposed to create test cases. However, these approaches, which rely on open-ended generation, encounter issues related to inefficiency and low attack success rates. In this work, we introduce a black-box approach that ingeniously exploits the unique properties of the nullspace to disentangle and regulate the crucial success information within test cases. Our study provides a brand-new perspective for automated red team research. Experimental results demonstrate that our approach outperforms baseline methods regarding the attack success rate. The generated test cases also excel in aspects of diversity and fluency.