Ada-DeVL: Adaptive Decoupling of Visual and Logical Reasoning Pathways for Efficient MLLMs

Haoyuan Fan, Jie Zhao, Yufeng Shi, Wengang Zhou, Houqiang Li


Abstract
Scaling test-time computation in Multimodal Large Language Models (MLLMs) enforces heavy visual analysis and long logical reasoning uniformly across queries, leading to severe token waste and overthinking. We propose **Ada-DeVL**, a framework that decouples visual perception depth from logical reasoning intensity, allowing the model to adaptively select one of four visuo-reasoning pathways according to problem complexity. To learn this adaptive behavior, we first apply a Self-Distillation Supervised Fine-Tuning (SFT) stage that generates difficulty-aligned, hallucination-reduced data while avoiding the exposure bias of cross-model distillation. We then use Group Relative Policy Optimization (GRPO) with a composite reward, incorporating diversity and format-adherence constraints to prevent mode collapse and shortcut exploitation. Notably, on the MMMU benchmark, the Qwen2.5-VL-7B based Ada-DeVL achieves **54.0%** accuracy, surpassing Vision-SR1 while saving **39.6%** tokens; the Qwen3-VL-8B based model reaches **64.0%**, outperforming its vanilla counterpart and reducing token consumption by **44.6%**, and achieves competitive accuracy against the strong Qwen3-VL-8B-Thinking baseline with significantly lower token costs (averaging 1560.8 vs. 4889.0 tokens).
Anthology ID:
2026.emnlp-main.417
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
9540–9562
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URL:
https://aclanthology.org/2026.emnlp-main.417/
DOI:
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Cite (ACL):
Haoyuan Fan, Jie Zhao, Yufeng Shi, Wengang Zhou, and Houqiang Li. 2026. Ada-DeVL: Adaptive Decoupling of Visual and Logical Reasoning Pathways for Efficient MLLMs. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 9540–9562, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Ada-DeVL: Adaptive Decoupling of Visual and Logical Reasoning Pathways for Efficient MLLMs (Fan et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.417.pdf