MOXIE: Discovering Alternative Explanations for Biomedical Image Classifiers
This study addresses the limitation of traditional segment-wise explanation methods, which return a single explanation while overlooking how multiple image regions support predictions and how segmentation strategies influence outcomes. We propose MOXIE, a multi-objective evolutionary framework that employs the NSGA-II algorithm combined with diverse segmentation techniques, including SLIC and Felzenszwalb, to search for minimal image subsets that preserve classifier confidence. This approach generates a Pareto front of alternative explanations ranging from compact to high-fidelity representations, transcending the single-explanation paradigm by revealing the minimal contextual regions required for model decisions. Evaluated on blood cell and skin cancer datasets, MOXIE significantly outperforms LIME in terms of the hypervolume indicator and further exposes a confidence collapse issue inherent in the latter method.