9. The method of claim 1 , wherein the keyword repository is constructed by performing statistical analysis on at least one of the following: the textual data on the web pages crawled by a search engine from the web; and logged query data input by users.
9. The method of claim 1 , wherein the keyword repository is constructed by performing statistical analysis on at least one of the following: the textual data on the web pages crawled by a search engine from the web; and logged query data input by users. 10. The method of claim 9 , wherein the keyword repository is updated periodically to reflect recent changes in the collection of keywords used by the community of users on the web.