Robustness quantification: a new method for assessing the reliability of the predictions of a classifier
Adrián Detavernier, Jasper De Bock
TL;DR
The paper tackles the challenge of per-instance reliability for generative probabilistic classifiers under data scarcity and distribution shift. It introduces robustness quantification, an instance-specific reliability metric based on minimal perturbations of the joint distribution, and contrasts it with uncertainty quantification. The authors develop global and local perturbation schemes, derive closed-form robustness metrics for Naive Bayes, and demonstrate through synthetic experiments that robustness remains stable under adverse conditions while uncertainty degrades. They conclude robustness quantification provides a practical reliability signal and suggest combining it with uncertainty metrics and extending the framework to more complex models.
Abstract
Based on existing ideas in the field of imprecise probabilities, we present a new approach for assessing the reliability of the individual predictions of a generative probabilistic classifier. We call this approach robustness quantification, compare it to uncertainty quantification, and demonstrate that it continues to work well even for classifiers that are learned from small training sets that are sampled from a shifted distribution.
