1. A method for a deep question answering system, the method comprising: computing 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; excluding 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 increasing, by operation of one or more computer processors, 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.