arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2607.04625cs.CVcs.AI

用于长文档理解的分层证据驱动推理

Hierarchical Evidence-Driven Reasoning for Long Document Understanding

University of Science and Technology of China(中国科学技术大学);iFLYTEK Research(科大讯飞研究院)

Junyu Xiong, Yonghui Wang, Rongjian Gu, Chenyu Liu, Bing Yin, Wengang Zhou, Houqiang Li

AI总结:

针对现有多模态RAG管道面临的问题,提出分层证据驱动的多模态RAG框架HIEVI-RAG,通过四阶段管道,包括分层问题分解、粗视觉页面检索、细粒度页面验证和内存引导迭代生成,提升长文档理解,效果显著优于现有基线。

摘要:

检索增强生成(RAG)通过检索机制简化长文档理解,但现有多模态RAG管道面临挑战。我们引入HIEVI-RAG,一种用于封闭域文档理解的分层、证据驱动的多模态RAG框架,将复杂查询分解为四阶段管道,经评估其效果显著优于现有开源基线。

英文摘要:

Retrieval-Augmented Generation (RAG) streamlines long-document understanding by leveraging retrieval mechanisms to restrict input images to a highly curated subset. However, existing multimodal RAG pipelines primarily face two critical challenges: first, standard semantic similarity retrievers frequently fetch topically overlapping yet answer-void distractor pages that mislead downstream generation; second, rigid single-pass pipelines heavily depend on initial retrieval success, where any omission of core evidence inevitably causes cascading errors. To address these challenges, we introduce HIEVI-RAG, a hierarchical, evidence-driven multimodal RAG framework for closed-domain document understanding. HIEVI-RAG systematically factorizes complex queries into a cooperative four-stage pipeline: (1) hierarchical question decomposition to break multi-hop root queries into atomic child questions; (2) coarse visual page retrieval leveraging a multimodal retriever to fetch candidate pages based on semantic similarity; (3) fine-grained page verification via EVIAGENT, a specialized multi-page verifier trained with GRPO to execute cross-page reasoning over multi-image blocks; and (4) memory-guided iterative generation that leverages accumulated sub-question context to execute multi-round, dynamic reasoning over the prioritized sequence. Extensive evaluations across four benchmarks demonstrate the robust efficacy and synergy of our framework, which significantly outperforms existing open-source baselines and exceeds the strongest reported baseline by an average of 8.05% in accuracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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