Axiomatic Explanations for Visual Search, Retrieval, and Similarity Learning
This work addresses interpretability issues in visual search and recommendation systems used by billions, offering a novel framework that improves upon incremental methods.
The paper tackled the problem of explaining complex visual search and similarity models by proposing a unique axiomatic solution based on fair credit assignment, which generalizes existing explainability techniques and yields more consistent explanations with a fast kernel-based method requiring orders of magnitude fewer evaluations.
Visual search, recommendation, and contrastive similarity learning power technologies that impact billions of users worldwide. Modern model architectures can be complex and difficult to interpret, and there are several competing techniques one can use to explain a search engine's behavior. We show that the theory of fair credit assignment provides a $\textit{unique}$ axiomatic solution that generalizes several existing recommendation- and metric-explainability techniques in the literature. Using this formalism, we show when existing approaches violate "fairness" and derive methods that sidestep these shortcomings and naturally handle counterfactual information. More specifically, we show existing approaches implicitly approximate second-order Shapley-Taylor indices and extend CAM, GradCAM, LIME, SHAP, SBSM, and other methods to search engines. These extensions can extract pairwise correspondences between images from trained $\textit{opaque-box}$ models. We also introduce a fast kernel-based method for estimating Shapley-Taylor indices that require orders of magnitude fewer function evaluations to converge. Finally, we show that these game-theoretic measures yield more consistent explanations for image similarity architectures.