1. A method for improving search results from a meta-search engine that queries information sources containing document collections, comprising: receiving an original query with user selected keywords and user selected operators; the user selected operators defining relationships between the user selected keywords; identifying a set of information sources to be interrogated using the original query by performing one of: (a) receiving a set of user selected information sources, (b) automatically identifying a set of information sources, and (c) performing a combination of (a) and (b); the set of information sources identifying two or more information sources; translating at least one of the user selected operators of the original query that is not supported by one of the information sources in the set of information sources to an alternate operator that is supported by the one of the information sources in the set of information sources; submitting a selected one of the translated queries and the original query to each information source in the set of information sources; receiving answers from each information source for the query submitted thereto; filtering each set of answers received from each information source that satisfy one of the translated queries by removing the answers that do not satisfy the original query; for each filtered set of answers, computing a subsumption ratio of the number of filtered answers that satisfy the original query to the number of answers that satisfy the translated query; and using each computed subsumption ratio to perform one of: (d) reformulating a translated query; (e) modifying information sources in the set of information sources automatically identified at (b); and (f) performing a combination of (d) and (e).