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Bibliographic Details
Main Authors: Chang, Zhipeng, He, Ting, Hao, Wenrui
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2601.13608
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author Chang, Zhipeng
He, Ting
Hao, Wenrui
author_facet Chang, Zhipeng
He, Ting
Hao, Wenrui
contents Federated learning aggregates model updates from distributed clients, but standard first order methods such as FedAvg apply the same scalar weight to all parameters from each client. Under non-IID data, these uniformly weighted updates can be strongly misaligned across clients, causing client drift and degrading the global model. Here we propose Fisher-Informed Parameterwise Aggregation (FIPA), a second-order aggregation method that replaces client-level scalar weights with parameter-specific Fisher Information Matrix (FIM) weights, enabling true parameter-level scaling that captures how each client's data uniquely influences different parameters. With low-rank approximation, FIPA remains communication- and computation-efficient. Across nonlinear function regression, PDE learning, and image classification, FIPA consistently improves over averaging-based aggregation, and can be effectively combined with state-of-the-art client-side optimization algorithms to further improve image classification accuracy. These results highlight the benefits of FIPA for federated learning under heterogeneous data distributions.
format Preprint
id arxiv_https___arxiv_org_abs_2601_13608
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Fisher-Informed Parameterwise Aggregation for Federated Learning with Heterogeneous Data
Chang, Zhipeng
He, Ting
Hao, Wenrui
Machine Learning
Federated learning aggregates model updates from distributed clients, but standard first order methods such as FedAvg apply the same scalar weight to all parameters from each client. Under non-IID data, these uniformly weighted updates can be strongly misaligned across clients, causing client drift and degrading the global model. Here we propose Fisher-Informed Parameterwise Aggregation (FIPA), a second-order aggregation method that replaces client-level scalar weights with parameter-specific Fisher Information Matrix (FIM) weights, enabling true parameter-level scaling that captures how each client's data uniquely influences different parameters. With low-rank approximation, FIPA remains communication- and computation-efficient. Across nonlinear function regression, PDE learning, and image classification, FIPA consistently improves over averaging-based aggregation, and can be effectively combined with state-of-the-art client-side optimization algorithms to further improve image classification accuracy. These results highlight the benefits of FIPA for federated learning under heterogeneous data distributions.
title Fisher-Informed Parameterwise Aggregation for Federated Learning with Heterogeneous Data
topic Machine Learning
url https://arxiv.org/abs/2601.13608