14. The method of claim 1 including, in a case that a user expresses an interest or expertise that has a corresponding encyclopedic document, using Wikipedia as a knowledge base, to form vector space matching with other objects.
14. The method of claim 1 including, in a case that a user expresses an interest or expertise that has a corresponding encyclopedic document, using Wikipedia as a knowledge base, to form vector space matching with other objects. 15. The method of claim 14 including, since the domain of data in the category space representation are binary, computing the similarity of two objects by computing the Jaccard coefficient which measures the degree of similarity between two sets.