Les erreurs de reconstruction : une explication simple et efficace pour les auto-encodeurs de graphe utilisés pour la détection d'anomalies
Abstract
Graph Auto-Encoders (GAEs) have demonstrated remarkable effectiveness in detecting
anomalies in graphs. However, their "black-box" nature makes it difficult to understand why
they classify a node as anomalous. Moreover, despite the development of XAI, where many
methods have been proposed to provide explanations for various deep learning models, there
is a notable lack of an evaluation framework dedicated to anomaly detection in graphs. Our
contribution addresses this gap by adapting existing evaluation frameworks to the specific challenges
of anomaly detection using GAEs. Additionally, it introduces a simple yet effective
explanation technique based on GAE reconstruction errors. Using this new framework, we
evaluate the effectiveness of different explainers and experimentally show that the method we
propose, based on reconstruction errors, outperforms other explainers for GAEs.