Efficient GNN Explanation via Learning Removal-based Attribution
Yao Rong Guanchu Wang Qizhang Feng Ninghao Liu Zirui Liu Enkelejda Kasneci Xia Hu
As Graph Neural Networks (GNNs) have been widely used in real-world
applications, model explanations are required not only by users but also by
legal regulations. However, simultaneously achieving high fidelity and low
computational costs in generating explanations has been a challenge for current
methods. In this work, we propose a framework of GNN explanation named LeArn
Removal-based Attribution (LARA) to address this problem. Specifically, we
introduce removal-based attribution and demonstrate its substantiated link to
interpretability fidelity theoretically and experimentally. The explainer in
LARA learns to generate removal-based attribution which enables providing
explanations with high fidelity. A strategy of subgraph sampling is designed in
LARA to improve the scalability of the training process. In the deployment,
LARA can efficiently generate the explanation through a feed-forward pass. We
benchmark our approach with other state-of-the-art GNN explanation methods on
six datasets. Results highlight the effectiveness of our framework regarding
both efficiency and fidelity. In particular, LARA is 3.5 times faster and
achieves higher fidelity than the state-of-the-art method on the large dataset
ogbn-arxiv (more than 160K nodes and 1M edges), showing its great potential in
real-world applications. Our source code is available at
https://anonymous.4open.science/r/LARA-10D8/README.md.