mlsanityData to 7 Oct 2026

Empowering Lightweight MLLMs with Reasoning via Long CoT SFT

arXiv 2509.03321 ↗First posted 3 Sep 2025cs.CVcited by 2

On the map: LLM reasoning → Multimodal reasoning

also in 1 more
Abstract (arXiv)

While Reinforcement Learning with Verifiable Rewards has enhanced the reasoning of large-scale language models (LLMs), its efficacy for lightweight multimodal language models (MLLMs) with fewer than seven billion parameters remains underexplored. This paper investigates the role of long Chain-of-Thought (long CoT) data in enhancing the reasoning abilities of such MLLMs. Our findings demonstrate that Supervised Fine-Tuning (SFT) with long CoT data significantly improves MLLM reasoning. Furthermore, we observe that after this initial SFT phase, MLLMs can achieve additional performance gains through a subsequent RL stage. We conclude that a SFT stage with long CoT data is a critical prerequisite for developing the reasoning capabilities of lightweight MLLMs.

Key facts. Cited by 2 papers in the map (data through 7 Oct 2026). Placed in Multimodal reasoning, one of 17 directions in LLM reasoning. Builds on 18 of its 19 references that are in the map. First posted on arXiv 3 Sep 2025.

Builds on

18 of 19 references.

Closest ancestors · 8

Same direction, newest first

  1. 2025Advancing Multimodal Reasoning: From Optimized Cold Start to Staged Reinforcement Learning4 Jun
  2. 2025SFT or RL? An Early Investigation into Training R1-Like Reasoning Large Vision-Language Models10 Apr
  3. 2025VLM-R1: A Stable and Generalizable R1-style Large Vision-Language Model10 Apr
  4. 2025R1-Onevision: Advancing Generalized Multimodal Reasoning through Cross-Modal Formalization13 Mar
  5. 2025LMM-R1: Empowering 3B LMMs with Strong Reasoning Abilities Through Two-Stage Rule-Based RL10 Mar
  6. 2024DynaMath: A Dynamic Visual Benchmark for Evaluating Mathematical Reasoning Robustness of Vision Language Models29 Oct
  7. 2024Measuring Multimodal Mathematical Reasoning with MATH-Vision Dataset22 Feb
  8. 2023MathVista: Evaluating Mathematical Reasoning of Foundation Models in Visual Contexts3 Oct

Other references · 10

  1. 2025DeepSeek-R1: Incentivizing Reasoning Capability in LLMs via Reinforcement Learningcited by 6,146
  2. 2025DAPO: An Open-Source LLM Reinforcement Learning System at Scalecited by 2,678
  3. 2025Understanding R1-Zero-Like Training: A Critical Perspectivecited by 1,276
  4. 2024OlympiadBench: A Challenging Benchmark for Promoting AGI with Olympiad-Level Bilingual Multimodal Scientific Problemscited by 1,099
  5. 2025Does Reinforcement Learning Really Incentivize Reasoning Capacity in LLMs Beyond the Base Model?cited by 948
  6. 2024MathVerse: Does Your Multi-modal LLM Truly See the Diagrams in Visual Math Problems?cited by 573
  7. 2025TTRL: Test-Time Reinforcement Learningcited by 253
  8. 2025R1-Omni: Explainable Omni-Multimodal Emotion Recognition with Reinforcement Learningcited by 99
  9. 2025Vision-R1: Evolving Human-Free Alignment in Large Vision-Language Models via Vision-Guided Reinforcement Learningcited by 68
  10. 2025Rethinking Reflection in Pre-Trainingcited by 43

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Cited by year (2026 to 7 Oct)

Citing papers per year: 2026: 2.

2 papers.

Similar, not cited

Close in wording, no citation either way

  1. 2025Demystifying Long Chain-of-Thought Reasoning in LLMs
  2. 2025Reinforcement Fine-Tuning Powers Reasoning Capability of Multimodal Large Language Models
  3. 2025The Synergy Dilemma of Long-CoT SFT and RL: Investigating Post-Training Techniques for Reasoning VLMs
  4. 2026The Art of Efficient Reasoning: Data, Reward, and Optimization
  5. 2025Reinforced MLLM: A Survey on RL-Based Reasoning in Multimodal Large Language Models
  6. 2025Advancing Multimodal Reasoning via Reinforcement Learning with Cold Start
  7. 2025The Challenge of Teaching Reasoning to LLMs Without RL or Distillation
  8. 2025CARFT: Boosting LLM Reasoning via Contrastive Learning with Annotated Chain-of-Thought-based Reinforced Fine-Tuning