BeGin: Extensive Benchmark Scenarios and An Easy-to-use Framework for Graph Continual Learning
This work addresses the problem of underdeveloped graph continual learning for researchers by establishing benchmarks and a framework, though it is incremental as it builds on existing CL concepts for graph data.
The paper tackles the lack of standardized benchmarks and tools for graph continual learning by defining four incremental settings, providing 35 benchmark scenarios based on real-world graphs, and developing an easy-to-use modular framework called BeGin, which covers 3x more experimental combinations than previous benchmarks.
Continual Learning (CL) is the process of learning ceaselessly a sequence of tasks. Most existing CL methods deal with independent data (e.g., images and text) for which many benchmark frameworks and results under standard experimental settings are available. Compared to them, however, CL methods for graph data (graph CL) are relatively underexplored because of (a) the lack of standard experimental settings, especially regarding how to deal with the dependency between instances, (b) the lack of benchmark datasets and scenarios, and (c) high complexity in implementation and evaluation due to the dependency. In this paper, regarding (a) we define four standard incremental settings (task-, class-, domain-, and time-incremental) for node-, link-, and graph-level problems, extending the previously explored scope. Regarding (b), we provide 35 benchmark scenarios based on 24 real-world graphs. Regarding (c), we develop BeGin, an easy and fool-proof framework for graph CL. BeGin is easily extended since it is modularized with reusable modules for data processing, algorithm design, and evaluation. Especially, the evaluation module is completely separated from user code to eliminate potential mistakes. Regarding benchmark results, we cover 3x more combinations of incremental settings and levels of problems than the latest benchmark. All assets for the benchmark framework are publicly available at https://github.com/ShinhwanKang/BeGin.