20. The computer system of claim 15 , wherein the obtained search category selection rules specify that the total number of the data entries having search category preference information which corresponds to a search category is used for identifying the search categories.
20. The computer system of claim 15 , wherein the obtained search category selection rules specify that the total number of the data entries having search category preference information which corresponds to a search category is used for identifying the search categories. 21. The computer system of claim 20 , wherein the computing device determines the order of the identified search categories based on the total number of the data entries having search category preference information which corresponds to one of the identified search categories.