Internalized Reasoning for Long-Context Visual Document Understanding
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Abstract (arXiv)
Visual long-document understanding is critical for enterprise, legal, and scientific applications, yet the best performing open recipes have not explored reasoning, a capability which has driven leaps in math and code performance. We introduce a synthetic data pipeline for reasoning in long-document understanding that generates thinking traces by scoring each page for question relevance, extracting textual evidence and ordering it from most to least relevant. We apply SFT to the resulting traces within texttt<think> tags, gated by a texttt<cot> control token, and the resulting reasoning capability is internalized via low-strength model merging. We study Qwen3 VL 32B and Mistral Small 3.1 24B. With Qwen3 VL, we achieve 58.3 on MMLongBenchDoc, surpassing the 7× larger Qwen3 VL 235B A22B (57.0). With Mistral, we show that synthetic reasoning outperforms distillation from the Thinking version's traces by 3.8 points on MMLBD-C, and internalized reasoning exhibits 12.4× fewer mean output tokens compared to explicit reasoning. We release our pipeline for reproducibility and further exploration.
Key facts. No citing papers in the map yet (data through 7 Oct 2026). Builds on 39 of its 49 references that are in the map. First posted on arXiv 31 Mar 2026.
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References · 39
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- 2024Quiet-STaR: Language Models Can Teach Themselves to Think Before Speakingcited by 292
- 2024Chain of Thought Empowers Transformers to Solve Inherently Serial Problemscited by 256
27 more
- 2024Self-Preference Bias in LLM-as-a-Judgecited by 248
- 2021Thinking Like Transformerscited by 182
- 2023SlideVQA: A Dataset for Document Visual Question Answering on Multiple Imagescited by 175
- 2023Implicit Chain of Thought Reasoning via Knowledge Distillationcited by 165
- 2024How to Train Long-Context Language Models (Effectively)cited by 141
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- 2026How to Train Your Long-Context Visual Document Modelcited by 2
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- 2026TestHallVQA: Exploring LVLMs' Document-Level Reasoning under Redundant Contexts from Scientific Exams