cs.AIOct 21, 2026

NormTune: Norm-Guided Parameter-Efficient Fine-Tuning for Reasoning-Intensive Tasks

Authors: Zhangming Li, Qinghao Hu, Weifan Guan, Yifan Zhang, Peisong Wang, Jian Cheng

Organizations: 1The Key Laboratory of Cognition and Decision Intelligence for Complex Systems, Institute of Automation, Chinese Academy of Sciences · School of Artificial Intelligence, University of Chinese Academy of Sciences · 3AiRiA · School of Computer Science and Engineering, Nanjing University of Science and Technology

Abstract

Full fine-tuning has achieved remarkable success on reasoning-intensive tasks, but it often requires substantial GPU resource consumption. Parameter-efficient fine-tuning (PEFT) provides a promising alternative for reducing this cost, yet we observe a substantial performance gap on reasoning-intensive tasks. In this paper, we present three key observations showing that this gap is closely associated with norm-related under-adaptation, where PEFT produces markedly smaller weight-update norms than full fine-tuning. Based on these observations, we propose Norm-Guided Parameter-Efficient Fine-Tuning (NormTune), a simple yet effective strategy that adaptively strengthens insufficiently updated layers according to their weight-update norms. Extensive experiments show that NormTune consistently enhances multiple PEFT methods across challenging reasoning benchmarks. Specifically, when trained on S1K-1.1, integrating NormTune into rank-8 LoRA, Bone, and MoRA yields substantial average accuracy improvements of 24.24%, 11.33%, and 16.21% , respectively, across AIME 2024, MATH 500, GPQA, and AIME 2025. Moreover, NormTune-enhanced rank-256 LoRA, Bone, and MoRA achieve performance comparable to S1 full fine-tuning, with respective average gains of 2.17%, 0.93%, and 3.00% over this baseline.

Figures & tables

Appendix figures & tables9 assets

Supplementary material from the paper’s appendix.

Appendix

Explore similar work

CardsList
  1. Hierarchical Low-Rank Reparameterization for Parameter-Efficient Fine-Tuning

    Oct 27, 2026Rong Huang, Yi Xiong, Yuan-Yuan Cheng +1LLM Fine-TuningParameter-Efficient Fine-Tuning

  2. FoRA: Fisher-orthogonal Rank Adaptation for Parameter-Efficient Fine-Tuning

    May 28, 2026Juneyoung Park, Seongbae Lee, Han-Sang Lee +6LLM Fine-TuningAdapter Tuning

  3. ChainDoRA: Tensor-Train Factorized Weight-Decomposed Low-Rank Adaptation for Parameter-Efficient LLM Fine-Tuning

    Sep 8, 2026Ashfak Yeafi, Mehedi Hasan, Md Khairul IslamLLM Fine-TuningLow-Rank Adaptation