An approach is provided in which a knowledge manager computes a set of unreasonable answer probabilities based upon a corresponding set of answers. Each of the set of unreasonable answer probabilities indicate a likelihood that its corresponding answer is an unreasonable answer to a question received by the knowledge manager. The knowledge manager determines that one or more unreasonable answers are included in the set of answers based upon determining that their corresponding unreasonable answer probabilities are above a threshold. In turn, the knowledge manager removes the one or more unreasonable answers from the set of answers and provides a modified set of answers to a user.