Papers › Merging by Matching Models in Task Parameter Subspaces

Merging by Matching Models in Task Parameter Subspaces

7 Dec 2023arXiv:2312.04339archive 2025-07-28

Derek Tam, Mohit Bansal, Colin Raffel

Model merging aims to cheaply combine individual task-specific models into a single multitask model. In this work, we view past merging methods as leveraging different notions of a ''task parameter subspace'' in which models are matched before being merged. We connect the task parameter subspace of a given model to its loss landscape and formalize how this approach to model merging can be seen as solving a linear system of equations. While past work has generally been limited to linear systems that have a closed-form solution, we consider using the conjugate gradient method to find a solution. We show that using the conjugate gradient method can outperform closed-form solutions, enables merging via linear systems that are otherwise intractable to solve, and flexibly allows choosing from a wide variety of initializations and estimates for the ''task parameter subspace''. We ultimately demonstrate that our merging framework called ''Matching Models in their Task Parameter Subspace'' (MaTS) achieves state-of-the-art results in multitask and intermediate-task model merging. We release all of the code and checkpoints used in our work at https://github.com/r-three/mats.

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concatenate_scores r-three/mats/src/eval/utils.py official repository ran no licence file found · pointer only · 65659f0a52551e43 · report
prepare_batchOfEvalInfo r-three/mats/src/eval/utils.py official repository ran no licence file found · pointer only · 001b8f851cad7c3e · report
average r-three/mats/src/merging/average.py official repository unverified no licence file found · pointer only · 1f58f45fd3f59164 · report
cg_forward r-three/mats/src/merging/conjugateGradient_average.py official repository unverified no licence file found · pointer only · 8f9e07b0e7fec4c9 · report
cg_forwardBackward r-three/mats/src/merging/conjugateGradient_fisherMerging.py official repository unverified no licence file found · pointer only · 4ee4acc1889850cd · report
conjugateGradient_average r-three/mats/src/merging/conjugateGradient_average.py official repository unverified no licence file found · pointer only · b4a85591e4919f77 · report
conjugateGradient_diagonalFisher r-three/mats/src/merging/conjugateGradient_diagonalFisher.py official repository unverified no licence file found · pointer only · 9562fd0d3e9b02ab · report
conjugateGradient_fisherMerging r-three/mats/src/merging/conjugateGradient_fisherMerging.py official repository unverified no licence file found · pointer only · 18db893c37a2f806 · report

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