1. A method of providing search results comprising: receiving a first search query from a first user; providing to the first user first search results obtained in response to the first search query; determining whether a webpage selected by the first user from the first search results is valid or not; receiving a second search query from a second user; providing to the second user second search results obtained in response to the second search query if it is determined that the webpage selected by the first user is valid; and correcting the second search results obtained in response to the second search query and providing the corrected second search results to the second user if it is determined that the webpage selected by the first user is not valid and is included in the second search results.