Bagel: A Benchmark for Assessing Graph Neural Network Explanations
摘要
Evaluating interpretability approaches for graph neural networks (GNN) specifically is known to be challenging due to the lack of a commonly accepted benchmark. Given a GNN model, several interpretability approaches exist to explain GNN models with diverse (sometimes conflicting) evaluation methodologies. In this paper, we propose a benchmark for evaluating the explainability approaches for GNNs called Bagel. In Bagel, we first propose four diverse GNN explanation evaluation regimes – 1) faithfulness, 2) sparsity, 3) correctness, and 4) plausibility. We reconcile multiple evaluation metrics in the existing literature and cover diverse notions for a holistic evaluation. Our graph datasets range from citation networks and document graphs to graphs from molecules and proteins. We conduct an extensive empirical study on four GNN models and nine post-hoc explanation approaches for node and graph classification tasks. We release both the benchmarks and reference implementations and make them available at https://github.com/Mandeep-Rathee/Bagel-benchmark .