Quantifying the knowledge in Deep Neural Networks: an overview

Deep Neural Networks (DNNs) have proven to be extremely effective at learning a wide range of tasks. Due to their complexity and frequently inexplicable internal state, DNNs are difficult to analyze: their black-box nature makes it challenging for humans to comprehend their internal behavior. Several attempts to interpret their operation have been made during the last decade, but analyzing deep neural models from the perspective of the knowledge encoded in their layers is a very promising research direction, which has barely been touched upon. Such a research approach could provide a more accurate insight into a DNN model, its internal state, learning progress, and knowledge storage capabilities. The purpose of this survey is two-fold: a) to review the concept of DNN knowledge quantification and highlight it as an important near-future challenge, as well as b) to provide a brief account of the scant existing methods attempting to actually quantify DNN knowledge. Although a few such algorithms have been proposed, this is an emerging topic still under investigation