Yumeng Wang


2025

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QUIDS: Query Intent Description for Exploratory Search via Dual Space Modeling
Yumeng Wang | Xiuying Chen | Suzan Verberne
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

In exploratory search, users often submit vague queries to investigate unfamiliar topics, but receive limited feedback about how the search engine understood their input. This leads to a self-reinforcing cycle of mismatched results and trial-and-error reformulation. To address this, we study the task of generating user-facing natural language query intent descriptions that surface what the system likely inferred the query to mean, based on post-retrieval evidence. We propose QUIDS, a method that leverages dual-space contrastive learning to isolate intent-relevant information while suppressing irrelevant content. QUIDS combines a dual-encoder representation space with a disentangling decoder that works together to produce concise and accurate intent descriptions. Enhanced by intent-driven hard negative sampling, the model significantly outperforms state-of-the-art baselines across ROUGE, BERTScore, and human/LLM evaluations. Our qualitative analysis confirms QUIDS’ effectiveness in generating accurate intent descriptions for exploratory search. Our work contributes to improving the interaction between users and search engines by providing feedback to the user in exploratory search settings.

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CALM: Unleashing the Cross-Lingual Self-Aligning Ability of Language Model Question Answering
Yumeng Wang | Zhiyuan Fan | Qingyun Wang | Yi R. Fung | Heng Ji
Findings of the Association for Computational Linguistics: NAACL 2025

Large Language Models (LLMs) are pretrained on extensive multilingual corpora to acquire both language-specific cultural knowledge and general knowledge. Ideally, while LLMs should provide consistent responses to culture-independent questions across languages, we observe significant performance disparities. To address this, we explore the **C**ross-Lingual Self-**A**ligning ability of **L**anguage **M**odels (**CALM**) to align knowledge across languages. Specifically, for a given question, we sample multiple responses across different languages and select the most self-consistent response as the target, leaving the remaining responses as negative examples. We then employ direct preference optimization (DPO) to align the model’s knowledge across different languages. Evaluations on the MEDQA and X-CSQA datasets demonstrate CALM’s effectiveness in enhancing cross-lingual knowledge question answering, both in zero-shot and retrieval-augmented settings. We also found that increasing the number of languages involved in CALM training leads to higher accuracy and consistency. We offer a qualitative analysis of how cross-lingual consistency can enhance knowledge alignment and explore the method’s generalizability.

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Unveiling the Lack of LVLM Robustness to Fundamental Visual Variations: Why and Path Forward
Zhiyuan Fan | Yumeng Wang | Sandeep Polisetty | Yi R. Fung
Findings of the Association for Computational Linguistics: ACL 2025

Large Vision Language Models (LVLMs) have shown impressive performance on various vision-language tasks. However, while objects in natural scenes inevitably exhibit visual variations in position, scale, orientation, and context due to changes in viewpoint and environment, the robustness of LVLMs to these fundamental visual variations remains largely unexplored. To address this gap, we introduce V²R-Bench, a comprehensive benchmark framework for evaluating Visual Variation Robustness of LVLMs, which encompasses automated evaluation dataset generation and principled metrics for thorough robustness assessment. Through extensive evaluation of 13 LVLMs, we reveal a surprising vulnerability to visual variations, affecting even advanced models that excel at complex vision-language tasks yet significantly underperform on simple tasks like object recognition. Interestingly, these models exhibit a distinct visual position bias that contradicts theories of effective receptive fields and demonstrate a human-like visual acuity threshold. To identify the source of these vulnerabilities, we propose a systematic framework for component-level analysis, featuring a novel visualization approach for aligned visual features. Results show that these vulnerabilities stem from error accumulation in the pipeline architecture and inadequate multimodal alignment. Complementary experiments with synthetic data further demonstrate that these limitations are fundamentally architectural challenges, underscoring the need for architectural innovations in future LVLM designs.