7. A computer program product for a user to curate a corpus of a cognitive computing system comprising: a computer-readable memory device which is not a propagating signal per se; and program instructions embodied by the computer-readable memory device which, when executed, cause a processor to perform steps of: producing a parse tree illustration of one or more discrepancies and confidence factors detected between at least a portion of a first document and a second or more documents in a cognitive computing system corpus, wherein the portion and the second or more documents comprise natural language unstructured data, wherein the parse tree illustration comprises a structure of a cluster of documents encapsulating categorized previously-asked questions about the corpus, and wherein the confidence factors are previously-assigned by a cognitive computing system corresponding to the questions and the documents; reporting on a user interface device to a user the parse tree illustration; responsive to receipt of a user selection of an illustrated discrepancy in the parse tree, displaying by a computing system on a user interface device to a user a drill-down dialog which shows at least a text string for the portion of the first document and at least one conflicting text string from the second or more documents, and which provides at least one user-selectable administrative action option for handling the detected discrepancy; and responsive to receipt of a user selection of at least one of the administrative action options, performing by the computing system the administrative action, thereby handling the detected discrepancy to curate the corpus.
11. The computer program product as set forth in claim 7 wherein the administrative action options comprise one or more actions selected from the group consisting of flagging the first document, removing the first document, replacing the first document, editing the first document, ignoring the discrepancy, flagging the second or more document, removing the second or more document, replacing the second or more document, and editing the second or more document.