Link Prediction in Bipartite Networks
Şükrü Demir İnan Özer, Günce Keziban Orman, Vincent Labatut
TL;DR
This work tackles link prediction in bipartite graphs, framing the problem with two node sets and a set of missing links. It evaluates 19 methods across three real datasets, spanning traditional scores, topological features, bipartite embeddings, and repurposed GCN-based recommender models. Key findings show that DiffRec, a GCN-based personalized recommender model, achieves high AUPR in sparse networks, while the Structural Perturbation Method remains a strong heuristic baseline; embedding-based and topological-feature methods generally underperform compared with supervised approaches. The study demonstrates the value of supervised graph representation learning tailored to bipartite link prediction and points to future directions involving ensembles and broader datasets.
Abstract
Bipartite networks serve as highly suitable models to represent systems involving interactions between two distinct types of entities, such as online dating platforms, job search services, or ecommerce websites. These models can be leveraged to tackle a number of tasks, including link prediction among the most useful ones, especially to design recommendation systems. However, if this task has garnered much interest when conducted on unipartite (i.e. standard) networks, it is far from being the case for bipartite ones. In this study, we address this gap by performing an experimental comparison of 19 link prediction methods able to handle bipartite graphs. Some come directly from the literature, and some are adapted by us from techniques originally designed for unipartite networks. We also propose to repurpose recommendation systems based on graph convolutional networks (GCN) as a novel link prediction solution for bipartite networks. To conduct our experiments, we constitute a benchmark of 3 real-world bipartite network datasets with various topologies. Our results indicate that GCN-based personalized recommendation systems, which have received significant attention in recent years, can produce successful results for link prediction in bipartite networks. Furthermore, purely heuristic metrics that do not rely on any learning process, like the Structural Perturbation Method (SPM), can also achieve success.
