Bridging Graph Network to Lifelong Learning with Feature Interaction
Authors: Chen Wang, Yuheng Qiu, Sebastian Scherer
Keywords: Graph Neural Network, Continual Learning
Abstract: Graph neural networks (GNN) are powerful models for many graph-structured tasks. In this paper, we aim to bridge GNN to lifelong learning, which is to overcome the effect of ``catastrophic forgetting" for continuously learning a sequence of graph-structured tasks. Although many lifelong learning techniques for convolutional neural networks (CNN) have been developed, lifelong learning for GNN is still underexplored and suffers from incomplete graph structure during learning. This is because in lifelong learning the nodes increase dynamically and can only be present to the model once, which makes many graph models and sampling strategies inapplicable. To solve this problem, we propose a new graph topology based on feature interaction, called the feature graph. It takes features as new nodes and turns nodes into independent graphs. This successfully converts the original problem of node classification to graph classification, in which the increasing nodes are turned into training samples. Therefore, the lifelong learning techniques developed for CNN become applicable to GNN for the first time. In the experiments, we demonstrate both the efficiency and effectiveness of feature graphs for lifelong learning tasks using a rehearsal method. We expect that it will have broad potential applications for graph-structured tasks in lifelong learning.