Jul 07, 2026
This work addresses the challenge of evaluating whether deep image classification models rely on task-relevant regions, given their opaque decision-making processes. To this end, the authors propose ReMoDEx, a novel framework that integrates local attribution methods—such as GradCAM++ and Integrated Gradients—with global heatmap clustering to enable systematic analysis from sample-level explanations to dataset-level decision patterns. By standardizing heatmaps, performing similarity-based clustering, and assessing spatial correlations, ReMoDEx uncovers shortcut learning behaviors invisible to conventional evaluation metrics. Applied to a COVID-19 chest X-ray classification task, the framework reveals two dominant model strategies: reliance on either the central thoracic region or image borders. Occlusion experiments confirm the latter as a shortcut, despite the model achieving a test accuracy of 86.27% and an AUC of 0.9624.