System, method, and computer program product to identify changes in evidence used to answer questions by a deep question answering system, by identifying a first evidence related to a feature, the deep question answering system having identified the feature as being relevant to answering a first type of question of a plurality of types of questions, and responsive to: (i) detecting a change in the first evidence, and (ii) determining that a confidence score of a first response generated for a first question, of the first type of question, exceeds a confidence threshold, generating an updated response for the first question based on the changed first evidence.