Characterizing the Influence of Topology on Graph Learning Tasks
Kailong Wu, Yule Xie, Jiaxin Ding, Yuxiang Ren, Luoyi Fu, Xinbing Wang, Chenghu Zhou
TL;DR
This work addresses how graph topology influences GNN performance by introducing TopoInf, an edge-level metric that quantifies the compatibility between topology and downstream tasks through a graph-filter perspective. By modeling topology via $\boldsymbol{f}(\mathbf{A})$ and the ideal signal $\mathbf{L}$, the authors define a global compatibility score $\mathcal{C}(\mathbf{A})=\mathcal{I}(\mathbf{A})-\lambda\mathcal{R}(\mathbf{A})$ and an edge-wise influence measure $\nabla\mathcal{C}_{\mathbf{A}}(e_{ij})$, enabling local topology analysis and optimization. Theoretical grounding is provided via contextual SBMs, showing how the bias term $\|\boldsymbol{f}(\mathbf{A})\mathbf{L}-\mathbf{L}\|$ and the regularization term $\|\boldsymbol{f}(\mathbf{A})\|$ jointly shape learning, complemented by motivating experiments and extensive real-data validation. Empirically, TopoInf-guided topology modification and DropEdge strategies improve performance across nine GNNs and multiple datasets, demonstrating practical utility for topology-aware graph learning and interpretability.
Abstract
Graph neural networks (GNN) have achieved remarkable success in a wide range of tasks by encoding features combined with topology to create effective representations. However, the fundamental problem of understanding and analyzing how graph topology influences the performance of learning models on downstream tasks has not yet been well understood. In this paper, we propose a metric, TopoInf, which characterizes the influence of graph topology by measuring the level of compatibility between the topological information of graph data and downstream task objectives. We provide analysis based on the decoupled GNNs on the contextual stochastic block model to demonstrate the effectiveness of the metric. Through extensive experiments, we demonstrate that TopoInf is an effective metric for measuring topological influence on corresponding tasks and can be further leveraged to enhance graph learning.
