Leap: Inductive Link Prediction via Learnable TopologyAugmentation
Ahmed E. Samy, Zekarias T. Kefato, Sarunas Girdzijauskas
TL;DR
LEAP tackles inductive link prediction by injecting topology information for new nodes through learnable anchor-based augmentations. It merges an MLP-Linker with a GNN operating on an augmented graph, enabling simultaneous use of node features and graph structure for unseen nodes. Across seven real-world graphs, LEAP consistently outperforms state-of-the-art baselines in both inductive and transductive settings, with notable gains in AUC and AP, especially on heterogeneous graphs. The approach offers a scalable, expressive framework for inductive graph learning and suggests future extensions to knowledge graphs and smarter anchor sampling strategies.
Abstract
Link prediction is a crucial task in many downstream applications of graph machine learning. To this end, Graph Neural Network (GNN) is a widely used technique for link prediction, mainly in transductive settings, where the goal is to predict missing links between existing nodes. However, many real-life applications require an inductive setting that accommodates for new nodes, coming into an existing graph. Thus, recently inductive link prediction has attracted considerable attention, and a multi-layer perceptron (MLP) is the popular choice of most studies to learn node representations. However, these approaches have limited expressivity and do not fully capture the graph's structural signal. Therefore, in this work we propose LEAP, an inductive link prediction method based on LEArnable toPology augmentation. Unlike previous methods, LEAP models the inductive bias from both the structure and node features, and hence is more expressive. To the best of our knowledge, this is the first attempt to provide structural contexts for new nodes via learnable augmentation in inductive settings. Extensive experiments on seven real-world homogeneous and heterogeneous graphs demonstrates that LEAP significantly surpasses SOTA methods. The improvements are up to 22\% and 17\% in terms of AUC and average precision, respectively. The code and datasets are available on GitHub (https://github.com/AhmedESamy/LEAP/)
