1. A computer program product for a deep question answering system, the computer program product comprising: a computer-readable storage medium having computer-readable program code embodied therewith, the computer-readable program code comprising: computer-readable program code configured to compute a concept score for a first concept in a first case received by the deep question answering system, wherein the concept score is based on a machine learning concept model for the first concept; computer-readable program code configured to exclude the first concept from consideration when analyzing a candidate answer and an item of supporting evidence to generate a response to the first case when the concept score does not exceed a predefined concept minimum weight threshold; and computer-readable program code configured to increase a weight applied to the first concept when analyzing the candidate answer and the item of supporting evidence to generate the response to the first case when the concept score exceeds a predefined maximum weight threshold.