Overview
A natural language search engine would in theory find targeted answers to user questions (as opposed to keyword search). For example, when confronted with a question of the form 'which U.S. state has the highest income tax?', conventional search engines ignore the question and instead search on the 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.
From a commercial standpoint, advertising on the results page could also be more relevant and could have a higher revenue potential than that of keyword search engines.
Read more about this topic: Natural Language User Interface