Federated Multi-Task Learning on Non-IID Data Silos: An Experimental Study
Yuwen Yang, Yuxiang Lu, Suizhi Huang, Shalayiding Sirejiding, Hongtao Lu, Yue Ding
TL;DR
This paper introduces FMTL-Bench, a comprehensive benchmark for Federated Multi-Task Learning (FMTL) on Non-IID data silos, integrating data, model, and optimization perspectives. It formalizes the FMTL objective, contrasts single-encoder multi-decoder (MD) and single-decoder conditioned (TC) architectures, and examines nine optimization baselines with parameter decoupling in federated contexts. Through seven data-partition experiments, multi-backbone model comparisons, and cross-domain scenarios, the authors analyze performance, scalability, and efficiency, including a case study on communication, time, and energy. Key insights show no universal winner across all settings, emphasize scenario-driven baseline selection, and highlight the benefits of pre-training and encoder-based decoupling for practical deployment, with code available for reproducibility.
Abstract
The innovative Federated Multi-Task Learning (FMTL) approach consolidates the benefits of Federated Learning (FL) and Multi-Task Learning (MTL), enabling collaborative model training on multi-task learning datasets. However, a comprehensive evaluation method, integrating the unique features of both FL and MTL, is currently absent in the field. This paper fills this void by introducing a novel framework, FMTL-Bench, for systematic evaluation of the FMTL paradigm. This benchmark covers various aspects at the data, model, and optimization algorithm levels, and comprises seven sets of comparative experiments, encapsulating a wide array of non-independent and identically distributed (Non-IID) data partitioning scenarios. We propose a systematic process for comparing baselines of diverse indicators and conduct a case study on communication expenditure, time, and energy consumption. Through our exhaustive experiments, we aim to provide valuable insights into the strengths and limitations of existing baseline methods, contributing to the ongoing discourse on optimal FMTL application in practical scenarios. The source code can be found on https://github.com/youngfish42/FMTL-Benchmark .
