Feature Attribution in Directed Acyclic Graphs Using Edge Intervention
Provides a more nuanced feature attribution for causal models, addressing limitations of node-centric approaches.
Existing Shapley value-based feature attribution methods fail to capture externality and exogenous influence of features in causal settings. DAG-SHAP treats each feature edge as an attribution object, achieving more reasonable interpretations, validated on real and synthetic datasets.
Shapley value-based feature attribution methods face challenges in scenarios involving complex feature interactions and causal relationships, even when a causal structure is provided. Existing methods typically adopt a node-centric view, attributing importance solely to individual features. Consequently, they often fail to simultaneously capture the externality and exogenous influence of features, leading to unreasonable interpretations. To overcome these limitations, we propose a novel feature attribution method called DAG-SHAP, which is based on edge intervention. DAG-SHAP treats each feature edge as an individual attribution object, ensuring that both externality and exogenous contributions of features are appropriately captured. Additionally, we introduce an approximation method for efficiently computing DAG-SHAP. Extensive experiments on both real and synthetic datasets validate the effectiveness of DAG-SHAP. Our code is available at https://github.com/ZJU-DIVER/DAG-SHAP.