Federated Learning Under Covariate Shifts with Generalization Guarantees

Abstract

This paper addresses intra-client and inter-client covariate shifts in federated learning (FL) with a focus on the overall generalization performance. To handle covariate shifts, we formulate a new global model training paradigm and propose Federated Importance-Weighted Empirical Risk Minimization (FTW-ERM) along with improving density ratio matching methods without requiring perfect knowledge of the supremum over true ratios. We also propose the communication-efficient variant FITW-ERM with the same level of privacy guarantees as those of classical ERM in FL. We theoretically show that FTW-ERM achieves smaller generalization error than classical ERM under certain settings. Experimental results demonstrate the superiority of FTW-ERM over existing FL baselines in challenging imbalanced federated settings in terms of data distribution shifts across clients.

Cite

Text

Ramezani-Kebrya et al. "Federated Learning Under Covariate Shifts with Generalization Guarantees." Transactions on Machine Learning Research, 2023.

Markdown

[Ramezani-Kebrya et al. "Federated Learning Under Covariate Shifts with Generalization Guarantees." Transactions on Machine Learning Research, 2023.](https://mlanthology.org/tmlr/2023/ramezanikebrya2023tmlr-federated/)

BibTeX

@article{ramezanikebrya2023tmlr-federated,
  title     = {{Federated Learning Under Covariate Shifts with Generalization Guarantees}},
  author    = {Ramezani-Kebrya, Ali and Liu, Fanghui and Pethick, Thomas and Chrysos, Grigorios and Cevher, Volkan},
  journal   = {Transactions on Machine Learning Research},
  year      = {2023},
  url       = {https://mlanthology.org/tmlr/2023/ramezanikebrya2023tmlr-federated/}
}