[R] Learning Explainable Models with Attribution Priors
I wanted to share this paper we recently submitted. TL;DR – the idea is that there has been a lot of recent research on explaining deep learning models by attributing importance to each input feature. We go one step farther and incorporate attribution priors – prior beliefs about what these feature attributions should look like – into the training process. We develop a fast, differentiable new feature attribution method called expected gradients, and optimize differentiable functions of these feature attributions to improve performance on a variety of tasks.
Our results include: In image classification, we encourage smoothness of nearby pixel attributions to get more coherent prediction explanations and robustness to noise. In drug response prediction, we encourage similarity of attributions among features that are connected in a protein-protein interaction graph to achieve more accurate predictions whose explanations correlate better with biological pathways. Finally, with health care data, we encourage inequality in the magnitude of feature attributions to build sparser models that perform better when training data is scarce. We hope this framework will be useful to anyone who wants to incorporate prior knowledge about how a deep learning model should behave in a given setting to improve performance.