Statistically Significant Concept-based Explanation of Image Classifiers via Model Knockoffs
Kaiwen Xu, Kazuto Fukuchi, Youhei Akimoto, Jun Sakuma
TL;DR
Concept-based explanations can mislead when false positives appear among interpretable factors. The authors propose a statistically grounded framework using Model-X Knockoff to select significant concepts while enforcing the false discovery rate at level $q$, applicable to both unsupervised (CSR-VAE) and supervised (CSR-CBM) concept learning. They prove an FDR guarantee and validate the approach on synthetic data and real datasets (Colored MNIST, CelebA), demonstrating improved interpretability without sacrificing predictive performance. By coupling sparse concept learning with Knockoff-based selection, the method provides reliable, human-understandable explanations that enhance trust in deep image classifiers.
Abstract
A concept-based classifier can explain the decision process of a deep learning model by human-understandable concepts in image classification problems. However, sometimes concept-based explanations may cause false positives, which misregards unrelated concepts as important for the prediction task. Our goal is to find the statistically significant concept for classification to prevent misinterpretation. In this study, we propose a method using a deep learning model to learn the image concept and then using the Knockoff samples to select the important concepts for prediction by controlling the False Discovery Rate (FDR) under a certain value. We evaluate the proposed method in our synthetic and real data experiments. Also, it shows that our method can control the FDR properly while selecting highly interpretable concepts to improve the trustworthiness of the model.
