Centrala begrepp
Incorporating diffusion distance and directional coherence into the counterfactual explanation generation process to produce more feasible and human-centric explanations.
Sammanfattning
The paper proposes a novel framework called CoDiCE (Coherent Directional Counterfactual Explainer) that enhances the search for counterfactual explanations by incorporating two key biases:
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Diffusion distance: This metric prioritizes transitions between data points that are highly interconnected through numerous short paths, ensuring the counterfactual points are feasible and respect the underlying data manifold.
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Directional coherence: This term promotes the alignment between the joint direction of changes in the counterfactual point and the marginal directions of individual feature changes, making the explanations more intuitive and consistent with human expectations.
The authors evaluate CoDiCE on both synthetic and real-world datasets with continuous and mixed-type features, and compare its performance against existing counterfactual explanation methods. The results demonstrate the effectiveness of the proposed approach in generating more feasible and directionally coherent counterfactual explanations.
The key insights are:
- Diffusion distance helps identify counterfactual points that are well-connected to the original input within the data manifold, improving the feasibility of the explanations.
- Directional coherence ensures the counterfactual suggestions align with the expected marginal effects of individual feature changes, making the explanations more intuitive and human-centric.
- There is a trade-off between the two biases, highlighting the importance of a balanced approach to counterfactual explanation generation.
The paper contributes to the field of Explainable AI by incorporating cognitive insights into the design of counterfactual explanation methods, moving towards more human-centric and interpretable machine learning systems.
Statistik
Diffusion distance between the original input and the counterfactual point is lower when using diffusion distance compared to L1 distance.
Directional coherence score is higher when using the directional coherence term in the objective function.
Citat
"Diffusion distance effectively weights more those points that are more interconnected by numerous short-length paths. This approach brings closely connected points nearer to each other, identifying a feasible path between them."
"Directional coherence formulates a bias designed to maintain consistency between the marginal (one feature at a time) and joint (multiple features simultaneously) directions in feature space needed to flip the outcome of the model's prediction."