) Exploration suggests to select the NPM that we are most uncertain about to improve our approxi-mation of the structure-property relationship. So, to balance exploitation and exploration, we must balance visits to regions of NPM feature space that (i) appear to contain high-performing NPMs and (ii) have not been explored well. A colloquial example of the exploitation-exploration dilemma in our lives is, in aiming to maximize our enjoyment of food, whether to choose a restaurant that we have visited and know we like versus a new one [ ].