Interpreting and Distinguishing Lack of an Answer in a Question Answering System

A mechanism is provided in a computing system for interpreting and distinguishing a lack of an answer to an input question. The mechanism receives an input question from a user. The mechanism generates one or more hypotheses based on a corpus of source information. The mechanism injects a no-answer response into the one or more hypotheses to form a plurality of candidate answers. The mechanism ranks the plurality of candidate answers based on evidence scoring and confidence scoring to form a candidate answer ranking. Responsive to determining the no-answer response is the top candidate answer in the candidate answer ranking, the mechanism presents the no-answer response to the user.