Mechanisms are provided for validating a candidate answer to an input question. A candidate answer to an input question is identified using a natural language processing of the input question and a corpus of information from which the candidate answer is identified. A validator is selected to apply to the candidate answer based on a characteristic of a correct answer for the input question. The validator is applied to the candidate answer to evaluate whether or not criteria of the validator are met by the candidate answer. Validation information is generated based the evaluation of whether or not criteria of the validator are met by the candidate answer. The validation information is stored in a validation status object associated with the input question.