Jiaheng Wei
Author directory2026
OFFSIDE: Benchmarking Unlearning Misinformation in Multimodal Large Language Models
Hao Zheng | Zirui Pang | Ling Li | Zhijie Deng | Yuhan Pu | Zhaowei Zhu | Xiaobo Xia | Jiaheng Wei
Findings of the Association for Computational Linguistics: ACL 2026
Hao Zheng | Zirui Pang | Ling Li | Zhijie Deng | Yuhan Pu | Zhaowei Zhu | Xiaobo Xia | Jiaheng Wei
Findings of the Association for Computational Linguistics: ACL 2026
Advances in Multimodal Large Language Models (MLLMs) intensify concerns about data safety, making Machine Unlearning (MU), the selective removal of harmful/private information, a critical necessity. However, existing MU benchmarks for MLLMs are limited by a lack of image diversity, coarse-grained unlearning target, and insufficient evaluation scenarios, which fail to capture the complexity of real-world applications. To facilitate the development of MLLMs unlearning and alleviate the aforementioned limitations, we introduce OFFSIDE, a novel benchmark for evaluating misinformation unlearning in MLLMs. This manually curated dataset contains 15.68K records for 80 players, providing a comprehensive framework with four test sets to assess forgetting efficacy, generalization, utility, and robustness. OFFSIDE supports advanced unlearning targets, such as fine-grained unlearning and visual rumor removal. Our extensive evaluation of multiple baselines not only extends key findings from LLM MU to MLLM MU: (1) unlearned rumors can be easily recovered through relearning and (2) all methods are vulnerable to prompt attacks, but also introduces novel insights in the context of MLLM: (1) unimodal methods fail to handle multimodal rumors, (2) unlearning efficacy is primarily driven by catastrophic forgetting statistically, and (3) all methods struggle with visual rumors (rumors embedded in images). These results expose significant vulnerabilities in current approaches, highlighting the need for more robust multimodal unlearning solutions.
Evian: Towards Explainable Visual Instruction-tuning Data Auditing
Zimu Jia | Mingjie Xu | Andrew Estornell | Jiaheng Wei
Findings of the Association for Computational Linguistics: ACL 2026
Zimu Jia | Mingjie Xu | Andrew Estornell | Jiaheng Wei
Findings of the Association for Computational Linguistics: ACL 2026
The efficacy of Large Vision-Language Models (LVLMs) is critically dependent on the quality of their training data, requiring a precise balance between visual fidelity and instruction-following capability. Existing datasets, however, are plagued by inconsistent quality, and current data filtering methods rely on coarse-grained scores that lack the granularity to identify nuanced semantic flaws like logical fallacies or factual errors. This creates a fundamental bottleneck in developing more reliable models. To address this, we make three core contributions. First, we construct a large-scale, 300K-sample benchmark by systematically injecting diverse, subtle defects to provide a challenging testbed for data auditing. Second, we introduce a novel “Decomposition-then-Evaluation” paradigm that breaks model responses into constituent cognitive components: visual description, subjective inference, and factual claim, enabling targeted analysis. Third, we instantiate this paradigm via EVIAN (Explainable Visual Instruction-tuning Data AuditiNg), an automated framework that evaluates these components along the orthogonal axes of Image-Text Consistency, Logical Coherence, and Factual Accuracy. Our empirical findings challenge the prevailing scale-centric paradigm: a model fine-tuned on a compact, high-quality subset curated by EVIAN consistently surpassed models trained on orders-of-magnitude larger datasets. We also reveal that dividing complex auditing into verifiable subtasks enables robust curation, and that Logical Coherence is the most critical factor in data quality evaluation.
IDEA: An Interpretable and Editable Decision-Making Framework for LLMs via Verbal-to-Numeric Calibration
Yanji He | Yuxin Jiang | Yiwen Wu | Bo Huang | Jiaheng Wei | Wei Wang
Findings of the Association for Computational Linguistics: ACL 2026
Yanji He | Yuxin Jiang | Yiwen Wu | Bo Huang | Jiaheng Wei | Wei Wang
Findings of the Association for Computational Linguistics: ACL 2026
Large Language Models are increasingly deployed for decision-making, yet their adoption in high-stakes domains remains limited by miscalibrated probabilities, unfaithful explanations, and inability to incorporate expert knowledge precisely. We propose IDEA, a framework that extracts LLM decision knowledge into an interpretable parametric model over semantically meaningful factors. Through joint learning of verbal-to-numerical mappings and decision parameters via EM, correlated sampling that preserves factor dependencies, and direct parameter editing with mathematical guarantees, IDEA produces calibrated probabilities while enabling quantitative human-AI collaboration. Experiments across five datasets show IDEA with Qwen-3-32B (78.6%) outperforms DeepSeek R1 (68.1%) and GPT-5.2 (77.9%), achieving perfect factor exclusion and exact calibration—precision unattainable through prompting alone.
VIDA: A Visual Intent-driven Design Assistant for Proactive Multimodal Clarification
Yanshan Liu | Hongbo Zhang | Zhen Sun | Jiaheng Wei | Kaishun Wu
Findings of the Association for Computational Linguistics: ACL 2026
Yanshan Liu | Hongbo Zhang | Zhen Sun | Jiaheng Wei | Kaishun Wu
Findings of the Association for Computational Linguistics: ACL 2026
In complex domains like interior design, user requests are often ambiguous and multimodal. Professional designers address this by asking strategic clarification questions based on hierarchical priorities, a capability lacking in current Vision-Language Models (VLMs). When fine-tuned on dialogue data, existing models often exhibit modality forgetting, overfitting to textual patterns while neglecting visual cues and thus producing hallucinated or visually irrelevant questions. To bridge this gap, we introduce VIDA (Visual Intent-driven Design Assistant), an assistant designed to generate proactive, visually grounded, and strategically prioritized clarification questions. Instead of standard fine-tuning, we propose a strategy-aware alignment framework that evolves from imitation learning to value-driven reinforcement. We utilize Group Sequence Policy Optimization to strictly enforce expert protocols, ensuring the model not only mimics fluent speech but also adheres to optimal inquiry strategies. Crucially, we design a novel hierarchical reward mechanism with Dynamic Intent Binding to align the assistant with professional prioritization standards. To facilitate this research, we construct and release InteriorClarify, a multimodal benchmark dataset comprising 1,016 real-world consultation cases annotated with this three-tier intent hierarchy. Extensive experiments demonstrate that VIDA sets a new state-of-the-art, improving the Strategic Alignment Score (SAS) by 20.59% over SFT baselines and effectively restoring visual grounding capabilities lost during standard fine-tuning.
When New Generators Arrive: Lifelong Machine-Generated Text Attribution via Ridge Feature Transfer
Zhen Sun | Yifan Liao | Zhicong Huang | Jiaheng Wei | Cheng Hong | Yutao Yue | Xinlei He
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zhen Sun | Yifan Liao | Zhicong Huang | Jiaheng Wei | Cheng Hong | Yutao Yue | Xinlei He
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Machine-generated text (MGT) attribution aims to identify the specific generator responsible for a given text, thereby providing fine-grained evidence for model accountability and misuse investigation. As new large language models continue to emerge, attribution models must continuously incorporate new generators while preserving their ability to recognize previously seen ones. Prior works have shown that this lifelong MGT attribution setting is challenging, and existing methods often struggle to achieve a stable balance between adapting to new classes and retaining old ones. To address this issue, we propose RidgeFT, a lightweight analytic update framework that does not rely on exemplar replay. RidgeFT trains a task-aware encoder on the initial generator set, stores compact class-wise sufficient statistics when each generator class is first observed, and then freezes the encoder for replay-free closed-form updates. It then suppresses generator-irrelevant variation through covariance calibration, improves representation capacity with fixed random features, and updates new classes through closed-form ridge regression based on class-level sufficient statistics. Across multi-topic evaluations with varying initial generator setups, consistently outperforms baselines. It achieves the best overall macro-F1 across domains, backbones, and incremental protocols, while also improving both old-class retention and new-class adaptation. These results suggest that feature-stable analytic updates provide a simple yet effective approach to lifelong MGT attribution.
DocFollow: A Hierarchical Fine-Grained Constraints Following Benchmark in Long Contexts for LLMs
Yanji He | Zhao Yang | Yuxin Jiang | Yiqian Yang | Jiaheng Wei | Wei Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Yanji He | Zhao Yang | Yuxin Jiang | Yiqian Yang | Jiaheng Wei | Wei Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large Language Models (LLMs) have demonstrated remarkable capabilities in processing long contexts and generating long-form texts. However, existing benchmarks evaluate these capabilities by focusing on either long-input comprehension with short outputs or short-input creative generation with lengthy outputs. This critical gap overlooks real-world Long-In-Long-Out Generation tasks, where models must simultaneously process long-context inputs and produce long-form outputs while adhering to fine-grained constraints. We introduce DocFollow, a comprehensive benchmark featuring 2,436 expert-validated instances across 5 major domains and 20 subdomains, designed to evaluate LLMs’ ability to follow hierarchical constraints in Document Following tasks. Our benchmark employs five types of constraints with increasing granularity. To ensure reliable evaluation, we develop a rule-based assessment protocol that decomposes overall evaluation uncertainty into atomic-level classification uncertainties, employing LLMs solely as information extractors for well-established NER and RE tasks rather than subjective scoring. Our evaluation of 13 state-of-the-art LLMs reveals a consistent pattern: while models maintain reasonable performance on coarse-grained constraints, they exhibit substantial degradation on fine-grained requirements, particularly entity-level constraints. This finding suggests fundamental architectural limitations in maintaining detailed structural and semantic fidelity throughout extended generation. Our findings highlight the critical need for advancing long-context generation capabilities beyond surface-level coherence to achieve precise fine-grained control. The implementation is publicly available. Source code is available at https://github.com/leonbig/DocFollow