Faithful Knowledge Graph Explanations for Commonsense Reasoning

While fusing language models (LMs) and knowledge graphs (KGs) has become common in commonsense question answering research, enabling faithful chain-of-thought explanations in these models remains an open problem. One major weakness of current KG-based explanation techniques is that they overlook the faithfulness of generated explanations during evaluation. To address this gap, we make two main contributions: (1) We propose and validate two quantitative metrics - graph consistency and graph fidelity - to measure the faithfulness of KG-based explanations. (2) We introduce Consistent GNN (CGNN), a novel training method that adds a consistency regularization term to improve explanation faithfulness. Our analysis shows that predictions from KG often diverge from original model predictions. The proposed CGNN approach boosts consistency and fidelity, demonstrating its potential for producing more faithful explanations. Our work emphasises the importance of explicitly evaluating suggest a path forward for developing architectures for faithful graph-based explanations.