To stand in the user perspective
 

Selected must be users will use it to search for words or phrases. Or think in this way: if I were the customer or search engine users: "I will how to search?" There is every time a customer find you ask him through what kind of search to. Such as for a enterprise for, because too familiar with their industry and their products, in the choice of time, easy to take it for granted that some is user will search, but the real user thinking and businessmen as not.