Underspecification and uncertainty in deep learning models: Is there a connection?
摘要
Deep learning has led to significant state-of-the-art results in a panoply of fields with its pattern recognition ability. Even though the research community has strongly benefited from this, these models showcase characteristics that hinder real-world application. One of the major hurdles is the difficulty in pinpointing what a neural network does not know along with their generalisation capabilities. In this context, the term underspecification has been coined, which describes the generation of different predictors with similar in-domain accuracy but diverging results in OOD. In this paper, we characterise the underspecification distribution and study its connection with epistemic uncertainty. We propose the average-metric epistemic uncertainty that transforms the epistemic uncertainty to the underspecification space. We perform a set of experiments using both LeNet and ResNet18 to solve classification problems on CIFAR-10 and Tiny-ImageNet, respectively. We verify that the average-metric epistemic uncertainty is able to accurately predict, on average, 95% of the predictors that can be obtained from a single architecture. In order to improve the interpretability of neural networks, we suggest utilising the range estimated by the average-metric epistemic uncertainty alongside the accuracy to characterise future state-of-the-art models.