Xinyu Fang


2025

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Redundancy Principles for MLLMs Benchmarks
Zicheng Zhang | Xiangyu Zhao | Xinyu Fang | Chunyi Li | Xiaohong Liu | Xiongkuo Min | Haodong Duan | Kai Chen | Guangtao Zhai
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

With the rapid iteration of Multi-modality Large Language Models (MLLMs) and the evolving demands of the field, the number of benchmarks produced annually has surged into the hundreds. The rapid growth has inevitably led to significant redundancy among benchmarks. Therefore, it is crucial to take a step back and critically assess the current state of redundancy and propose targeted principles for constructing effective MLLM benchmarks. In this paper, we focus on redundancy from three key perspectives: 1) Redundancy of benchmark capability dimensions, 2) Redundancy in the number of test questions, and 3) Cross-benchmark redundancy within specific domains. Through the comprehensive analysis over hundreds of MLLMs’ performance across more than 20 benchmarks, we aim to quantitatively measure the level of redundancy lies in existing MLLM evaluations, provide valuable insights to guide the future development of MLLM benchmarks, and offer strategies to refine and address redundancy issues effectively.

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OmniAlign-V: Towards Enhanced Alignment of MLLMs with Human Preference
Xiangyu Zhao | Shengyuan Ding | Zicheng Zhang | Haian Huang | Maosongcao Maosongcao | Jiaqi Wang | Weiyun Wang | Xinyu Fang | Wenhai Wang | Guangtao Zhai | Hua Yang | Haodong Duan | Kai Chen
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Recent advancements in open-source multi-modal large language models (MLLMs) have primarily focused on enhancing foundational capabilities, leaving a significant gap in human preference alignment. This paper introduces OmniAlign-V, a comprehensive dataset of 200K high-quality training samples featuring diverse images, complex questions, and varied response formats to improve MLLMs’ alignment with human preferences. We also present MM-AlignBench, a human-annotated benchmark specifically designed to evaluate MLLMs’ alignment with human values. Experimental results show that finetuning MLLMs with OmniAlign-V, using Supervised Fine-Tuning (SFT) or Direct Preference Optimization (DPO), significantly enhances human preference alignment while maintaining or enhancing performance on standard VQA benchmarks, preserving their fundamental capabilities.

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Do Vision-Language Models Have Internal World Models? Towards an Atomic Evaluation
Qiyue Gao | Xinyu Pi | Kevin Liu | Junrong Chen | Ruolan Yang | Xinqi Huang | Xinyu Fang | Lu Sun | Gautham Kishore | Bo Ai | Stone Tao | Mengyang Liu | Jiaxi Yang | Chao-Jung Lai | Chuanyang Jin | Jiannan Xiang | Benhao Huang | Zeming Chen | David Danks | Hao Su | Tianmin Shu | Ziqiao Ma | Lianhui Qin | Zhiting Hu
Findings of the Association for Computational Linguistics: ACL 2025

Internal world models (WMs) enable agents to understand the world’s state and predict transitions, serving as the basis for advanced deliberative reasoning.Recent large Vision-Language Models (VLMs), such as GPT-4o and Gemini, exhibit potential as general-purpose WMs. While the latest studies have evaluated and shown limitations in specific capabilities such as visual understanding, a systematic evaluation of VLMs’ fundamental WM abilities remains absent. Drawing on comparative psychology and cognitive science, we propose a two-stage framework that assesses **perception** (visual, spatial, temporal, quantitative, and motion) and **prediction** (mechanistic simulation, transitive inference, compositional inference) to provide an atomic evaluation of VLMs as WMs. Guided by this framework, we introduce **WM-ABench**, a large-scale benchmark comprising 23 fine-grained evaluation dimensions across 6 diverse simulated environments with controlled counterfactual simulations. Through 660 experiments on 15 latest commercial and open-source VLMs, we find that these models exhibit striking limitations in basic world modeling abilities. For instance, all models perform at near-random accuracy when distinguishing motion trajectories. Additionally, they lack disentangled understanding—e.g., they tend to believe blue objects move faster than green ones. More rich results and analyses reveal significant gaps between VLMs and human-level world modeling.

2024

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ProSA: Assessing and Understanding the Prompt Sensitivity of LLMs
Jingming Zhuo | Songyang Zhang | Xinyu Fang | Haodong Duan | Dahua Lin | Kai Chen
Findings of the Association for Computational Linguistics: EMNLP 2024

Large language models (LLMs) have demonstrated impressive capabilities across various tasks, but their performance is highly sensitive to the prompts utilized. This variability poses challenges for accurate assessment and user satisfaction. Current research frequently overlooks instance-level prompt variations and their implications on subjective evaluations. To address these shortcomings, we introduce ProSA, a framework designed to evaluate and comprehend prompt sensitivity in LLMs. ProSA incorporates a novel sensitivity metric, PromptSensiScore, and leverages decoding confidence to elucidate underlying mechanisms. Our extensive study, spanning multiple tasks, uncovers that prompt sensitivity fluctuates across datasets and models, with larger models exhibiting enhanced robustness. We observe that few-shot examples can alleviate this sensitivity issue, and subjective evaluations are also susceptible to prompt sensitivities, particularly in complex, reasoning-oriented tasks. Furthermore, our findings indicate that higher model confidence correlates with increased prompt robustness. We believe this work will serve as a helpful tool in studying prompt sensitivity of LLMs. The project is released at: https://github.com/open-compass/ProSA.