论文标题
通过图形反事实公平学习公平节点表示
Learning Fair Node Representations with Graph Counterfactual Fairness
论文作者
论文摘要
公平的机器学习旨在减轻模型预测的偏见,以针对诸如种族和性别等敏感属性的某些亚群。在许多现有的公平概念中,反事实公平性从因果角度来衡量模型的公平性,通过比较原始数据和反事实的预测。在反事实中,该个体的敏感属性值已被修改。最近,一些作品将反事实公平扩展到图形数据,但其中大多数忽略了可能导致偏见的以下事实:1)每个节点邻居的敏感属性可能因果关系可能会影响预测W.R.T.这个节点; 2)敏感属性可能会影响其他特征和图形结构。为了解决这些问题,在本文中,我们提出了一个新颖的公平概念 - 图形反事实公平,该公平考虑了上述事实的偏见。为了学习针对图形反事实公平性的节点表示,我们提出了一个基于反事实数据增强的新框架。在此框架中,我们生成对应于每个节点及其邻居敏感属性的扰动的反事实。然后,我们通过最大程度地减少从原始图和每个节点的反事实的表示之间的差异来实现公平性。在合成图和现实世界图上进行的实验表明,我们的框架在图形反事实公平性中的表现优于最先进的基线,并且还可以实现可比的预测性能。
Fair machine learning aims to mitigate the biases of model predictions against certain subpopulations regarding sensitive attributes such as race and gender. Among the many existing fairness notions, counterfactual fairness measures the model fairness from a causal perspective by comparing the predictions of each individual from the original data and the counterfactuals. In counterfactuals, the sensitive attribute values of this individual had been modified. Recently, a few works extend counterfactual fairness to graph data, but most of them neglect the following facts that can lead to biases: 1) the sensitive attributes of each node's neighbors may causally affect the prediction w.r.t. this node; 2) the sensitive attributes may causally affect other features and the graph structure. To tackle these issues, in this paper, we propose a novel fairness notion - graph counterfactual fairness, which considers the biases led by the above facts. To learn node representations towards graph counterfactual fairness, we propose a novel framework based on counterfactual data augmentation. In this framework, we generate counterfactuals corresponding to perturbations on each node's and their neighbors' sensitive attributes. Then we enforce fairness by minimizing the discrepancy between the representations learned from the original graph and the counterfactuals for each node. Experiments on both synthetic and real-world graphs show that our framework outperforms the state-of-the-art baselines in graph counterfactual fairness, and also achieves comparable prediction performance.