12. The computer program product of claim 8 , wherein the knowledge base is a corpus of natural language documents, and wherein the query is applied to the corpus by the QA system to identify the candidate sub-portion of content.
12. The computer program product of claim 8 , wherein the knowledge base is a corpus of natural language documents, and wherein the query is applied to the corpus by the QA system to identify the candidate sub-portion of content. 13. The computer program product of claim 12 , wherein: the QA system returns a plurality of candidate answers to the query, identifying the candidate sub-portion of content comprises selecting, by the correction engine, a candidate answer from the plurality of candidate answers as the candidate sub-portion of content based on confidence measures for each of the plurality of candidate answers, and correcting, by the correction engine, the sub-portion using the identified candidate sub-portion of content to generate a corrected natural language document comprises: configuring the correction engine to compare the confidence measure for the selected candidate answer to a threshold confidence measure; comparing, by the correction engine, the confidence measure for the selected candidate answer to the threshold confidence measure; configuring the correction engine to perform one of automatic correction of the erroneous subportion using the identified candidate sub-portion or sending a notification to a user indicating the erroneous sub-portion, the candidate sub-portion, and requesting authorization to perform the correction, based on results of comparing the confidence measure for the selected candidate answer to the threshold confidence measure; and performing, by the correction engine, one of the automatic correction of the erroneous sub-portion using the identified candidate sub-portion or sending the notification to the user indicating the erroneous sub-portion, the candidate sub-portion and requesting authorization to perform the correction, based on the results of comparing the confidence measure for the selected candidate answer to the threshold confidence measure.