8. The computer program product as set forth in claim 7 further comprising program instructions stored by the computer readable, tangible storage device, which, when executed by a processor, cause a computing platform to: for the first user and a third question, extract by a natural language processor one or more user preferences and one or more sentiment levels, wherein each user preference and each sentiment level is associated with the third question, or associated with the first user, or associated with both the third question and the first user; search semantically on the third question; receive a plurality of candidate answers from the semantic search on the third question; selecting by a computer one or more of the received candidate answers from the search on the third question, wherein the selection is performed according to a combination of the one or more sentiment levels and according to the one or more user preferences associated with the first and second users and with the first, second and third questions; and produce a third user output including the selected one or more candidate answers selected from the search on the third question.
8. The computer program product as set forth in claim 7 further comprising program instructions stored by the computer readable, tangible storage device, which, when executed by a processor, cause a computing platform to: for the first user and a third question, extract by a natural language processor one or more user preferences and one or more sentiment levels, wherein each user preference and each sentiment level is associated with the third question, or associated with the first user, or associated with both the third question and the first user; search semantically on the third question; receive a plurality of candidate answers from the semantic search on the third question; selecting by a computer one or more of the received candidate answers from the search on the third question, wherein the selection is performed according to a combination of the one or more sentiment levels and according to the one or more user preferences associated with the first and second users and with the first, second and third questions; and produce a third user output including the selected one or more candidate answers selected from the search on the third question. 9. The computer program product as set forth in claim 8 further comprising program instructions stored by the computer readable, tangible storage device, which, when executed by a processor, cause a computing platform to detect that the first question is similar to at least the third question.