A search engine for databases, data streams, and other data sources allows user preferences as to the relative importance of search criteria to be used to rank the output of the search engine. A weighted preference generator generates weighted preference information including at least a plurality of weights corresponding to a plurality of search criteria. A weighted preference data search engines uses the weighted preference information to search a data source and to provide an ordered result list based upon the weighted preference information. A method for weighted preference data searching includes determining weighted preference information including a plurality of search criteria and a corresponding plurality of weights signifying the relative importance of the search criteria, and querying a data source and ranking the results based upon the weighted preference information. In addition to allowing client input of the relative importance of various search criteria, the system and method also preferably include the ability to provide a subjective ordering for at least some of the search criteria.