Federated Learning is emerging as a privacy-preserving model training
approach in distributed edge applications. As such, most edge deployments are
heterogeneous in nature i.e., their sensing capabilities and environments vary
across deployments. This edge heterogeneity violates the independence and
identical distribution (IID) property of local data across clients and produces
biased global models i.e. models that contribute to unfair decision-making and
discrimination against a particular community or a group. Existing bias
mitigation techniques only focus on bias generated from label heterogeneity in
non-IID data without accounting for domain variations due to feature
heterogeneity and do not address global group-fairness property.
Our work proposes a group-fair FL framework that minimizes group-bias while
preserving privacy and without resource utilization overhead. Our main idea is
to leverage average conditional probabilities to compute a cross-domain group
\textit{importance weights} derived from heterogeneous training data to
optimize the performance of the worst-performing group using a modified
multiplicative weights update method. Additionally, we propose regularization
techniques to minimize the difference between the worst and best-performing
groups while making sure through our thresholding mechanism to strike a balance
between bias reduction and group performance degradation. Our evaluation of
human emotion recognition and image classification benchmarks assesses the fair
decision-making of our framework in real-world heterogeneous settings.

我们提出了一个群体公平的联邦学习框架，旨在在保护隐私和没有资源利用开销的情况下，减少群体偏见。我们通过利用平均条件概率来计算由异构训练数据得出的跨领域群体重要性权重，使用修改的乘法权重更新方法来优化表现最差的群体的性能。此外，我们提出了正则化技术来最小化最差和最好表现群体之间的差异，同时通过阈值机制确保在减少偏见和群体表现下降之间取得平衡。我们对人类情绪识别和图像分类基准进行了评估，以评估我们的框架在实际异构环境中的公平决策能力。