STAR: Spectral Truncation and Rescale for Model Merging

Fuente: arXiv
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Main Authors: Lee, Yu-Ang, Ko, Ching-Yun, Pedapati, Tejaswini, Chung, I-Hsin, Yeh, Mi-Yen, Chen, Pin-Yu
Format: Preprint
Published: 2025
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author Lee, Yu-Ang
Ko, Ching-Yun
Pedapati, Tejaswini
Chung, I-Hsin
Yeh, Mi-Yen
Chen, Pin-Yu
author_facet Lee, Yu-Ang
Ko, Ching-Yun
Pedapati, Tejaswini
Chung, I-Hsin
Yeh, Mi-Yen
Chen, Pin-Yu
contents Model merging is an efficient way of obtaining a multi-task model from several pretrained models without further fine-tuning, and it has gained attention in various domains, including natural language processing (NLP). Despite the efficiency, a key challenge in model merging is the seemingly inevitable decrease in task performance as the number of models increases. In this paper, we propose $\mathbf{S}$pectral $\mathbf{T}$runcation $\mathbf{A}$nd $\mathbf{R}$escale (STAR) that aims at mitigating ``merging conflicts'' by truncating small components in the respective spectral spaces, which is followed by an automatic parameter rescaling scheme to retain the nuclear norm of the original matrix. STAR requires no additional inference on original training data and is robust to hyperparamater choice. We demonstrate the effectiveness of STAR through extensive model merging cases on diverse NLP tasks. Specifically, STAR works robustly across varying model sizes, and can outperform baselines by 4.2$\%$ when merging 12 models on Flan-T5. Our code is publicly available at https://github.com/IBM/STAR.
format Preprint
id arxiv_https___arxiv_org_abs_2502_10339
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle STAR: Spectral Truncation and Rescale for Model Merging
Lee, Yu-Ang
Ko, Ching-Yun
Pedapati, Tejaswini
Chung, I-Hsin
Yeh, Mi-Yen
Chen, Pin-Yu
Computation and Language
Artificial Intelligence
Machine Learning
Model merging is an efficient way of obtaining a multi-task model from several pretrained models without further fine-tuning, and it has gained attention in various domains, including natural language processing (NLP). Despite the efficiency, a key challenge in model merging is the seemingly inevitable decrease in task performance as the number of models increases. In this paper, we propose $\mathbf{S}$pectral $\mathbf{T}$runcation $\mathbf{A}$nd $\mathbf{R}$escale (STAR) that aims at mitigating ``merging conflicts'' by truncating small components in the respective spectral spaces, which is followed by an automatic parameter rescaling scheme to retain the nuclear norm of the original matrix. STAR requires no additional inference on original training data and is robust to hyperparamater choice. We demonstrate the effectiveness of STAR through extensive model merging cases on diverse NLP tasks. Specifically, STAR works robustly across varying model sizes, and can outperform baselines by 4.2$\%$ when merging 12 models on Flan-T5. Our code is publicly available at https://github.com/IBM/STAR.
title STAR: Spectral Truncation and Rescale for Model Merging
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2502.10339