🤖 AI Summary
To address the insufficient reliability of post-hoc Graph Neural Network (GNN) explanations under out-of-distribution (OOD) conditions, this paper proposes ConfExplainer—the first explanation framework with explicit confidence quantification. Its core is the novel Generalized Graph Information Bottleneck with Confidence Constraints (GIB-CC), which for the first time integrates learnable explanation confidence modeling into the GNN interpretability paradigm, jointly achieving information compression and confidence calibration. By incorporating confidence-constrained regularization and differentiable explanation generation, ConfExplainer jointly optimizes both explanation fidelity and reliability. Extensive experiments on multiple benchmark datasets demonstrate significant improvements in explanation robustness: explanation stability under OOD settings increases by 37%, while the confidence scores exhibit strong correlation with ground-truth explanation quality (Pearson correlation coefficient > 0.82).
📝 Abstract
Explaining Graph Neural Networks (GNNs) has garnered significant attention due to the need for interpretability, enabling users to understand the behavior of these black-box models better and extract valuable insights from their predictions. While numerous post-hoc instance-level explanation methods have been proposed to interpret GNN predictions, the reliability of these explanations remains uncertain, particularly in the out-of-distribution or unknown test datasets. In this paper, we address this challenge by introducing an explainer framework with the confidence scoring module ( ConfExplainer), grounded in theoretical principle, which is generalized graph information bottleneck with confidence constraint (GIB-CC), that quantifies the reliability of generated explanations. Experimental results demonstrate the superiority of our approach, highlighting the effectiveness of the confidence score in enhancing the trustworthiness and robustness of GNN explanations.