Abstract: Disclosed herein are a method, an apparatus, and a computer readable recording medium for a search using extension keyword. According to an aspect of the present invention, there is provided a method for a search using extension keyword, the method including mapping search keywords transmitted from a user terminal to at least one concept keyword, extending the concept keyword to plurality of concept keywords having association with each other so that a concept keyword extension data-set is generated, and generating extension keywords corresponding to the concept keyword extension data-set.

Abstract: A system to recommend a keyword includes a verifying unit to determine whether a keyword is a direct click keyword by referring to a click log and to determine whether the keyword is an indirect click keyword by referring to a third universal resource locator (URL) selected using the direct click keyword, wherein the direct click keyword is a keyword used to select a first URL on a computing device and the indirect click keyword is a keyword used to select a second URL on the computing device; and a keyword recommending unit to recommend the determined indirect click keyword. A method for recommending a keyword includes determining whether a keyword is a direct click keyword by referring to a click log; determining whether the keyword is an indirect click keyword by referring to a third URL selected using the direct click keyword; and recommending the determined indirect click keyword.

Abstract: A system to recommend a keyword includes a verifying unit to determine whether a keyword is a direct click keyword by referring to a click log and to determine whether the keyword is an indirect click keyword by referring to a third universal resource locator (URL) selected using the direct click keyword, wherein the direct click keyword is a keyword used to select a first URL on a computing device and the indirect click keyword is a keyword used to select a second URL on the computing device; and a keyword recommending unit to recommend the determined indirect click keyword. A method for recommending a keyword includes determining whether a keyword is a direct click keyword by referring to a click log; determining whether the keyword is an indirect click keyword by referring to a third URL selected using the direct click keyword; and recommending the determined indirect click keyword.