InA natural-language search engine would in theory find targeted [[question answering|answers to user questions]] (as opposed to a keyword search). For example, when confronted with a question of the form 'which [[United States|U.S.]] state has the highest [[income tax]]?', conventional search engines ignore the question and instead search on the [[index term|keywords]] 'state', 'income' and 'tax'. Natural-language search, on the other hand, attempts to use natural-language processing to understand the nature of the question and then to search and return a subset of the web that contains the answer to the question. If it works, results would have a higher relevance than results from a keyword search engine, due to the question being included.{{Citation needed|date=October 2015}}
