论文标题
分析GNN中抽样对个人公平性的影响
Analyzing the Effect of Sampling in GNNs on Individual Fairness
论文作者
论文摘要
基于图神经网络(GNN)方法已饱和推荐系统的领域。这些系统的收益很大,显示了通过网络结构解释数据的优势。但是,尽管在建议任务中使用图形结构有明显的好处,但这种表示形式也带来了新的挑战,这些挑战加剧了缓解算法偏见的复杂性。当将GNN集成到下游任务中时,例如建议,缓解偏差可能会变得更加困难。此外,将现有的公平促进方法应用于大型现实世界数据集的顽固性对缓解尝试更加严重的限制。我们的工作开始填补这一差距,方法是采用现有方法来促进图形上的个人公平性,并将其扩展以支持Mini Batch或基于子样本的GNN培训,从而为将此方法应用于下游建议任务奠定了基础。我们评估了两种流行的GNN方法:图形卷积网络(GCN),该方法在整个图上进行训练,以及使用概率随机步行的图形,以创建用于迷你批次训练的子图,并评估子采样对个人公平性的影响。我们实施了一个单独的公平概念,称为\ textit {redress},由Dong等人提出,该概念使用等级优化来学习单个公平节点或项目嵌入。我们在两个现实世界数据集上进行了经验表明,图形不仅能够达到可比的精度,而且与GCN模型相比,还可以提高公平性。这些发现对个人公平促进,GNN和下游形式产生了影响,推荐系统,表明小批量培训通过允许当地的细微努力指导代表性学习中的公平促进过程来促进个人公平促进。
Graph neural network (GNN) based methods have saturated the field of recommender systems. The gains of these systems have been significant, showing the advantages of interpreting data through a network structure. However, despite the noticeable benefits of using graph structures in recommendation tasks, this representational form has also bred new challenges which exacerbate the complexity of mitigating algorithmic bias. When GNNs are integrated into downstream tasks, such as recommendation, bias mitigation can become even more difficult. Furthermore, the intractability of applying existing methods of fairness promotion to large, real world datasets places even more serious constraints on mitigation attempts. Our work sets out to fill in this gap by taking an existing method for promoting individual fairness on graphs and extending it to support mini-batch, or sub-sample based, training of a GNN, thus laying the groundwork for applying this method to a downstream recommendation task. We evaluate two popular GNN methods: Graph Convolutional Network (GCN), which trains on the entire graph, and GraphSAGE, which uses probabilistic random walks to create subgraphs for mini-batch training, and assess the effects of sub-sampling on individual fairness. We implement an individual fairness notion called \textit{REDRESS}, proposed by Dong et al., which uses rank optimization to learn individual fair node, or item, embeddings. We empirically show on two real world datasets that GraphSAGE is able to achieve, not just, comparable accuracy, but also, improved fairness as compared with the GCN model. These finding have consequential ramifications to individual fairness promotion, GNNs, and in downstream form, recommender systems, showing that mini-batch training facilitate individual fairness promotion by allowing for local nuance to guide the process of fairness promotion in representation learning.