1. A method for grouping search results received from information sources, comprising: receiving a query with user-selected keywords to be evaluated in an information domain; identifying a plurality of information sources associated with the information domain; submitting the query to at least two of the plurality of information sources identified; receiving a set of search results from the at least two information source for the query submitted thereto; extracting a plurality of attributes from content in each set of search results received using information source wrappers; specifying a first set of the plurality of attributes, which defines a main clustering strategy, and a second set of the plurality of attributes, which defines a sub-clustering strategy; each clustering strategy defining a unique set of attributes that may be extracted from the content of search results using the information source wrappers; generating a main grouping of the sets of search results received from the information sources using the first set of attributes; the main grouping of search results including a plurality of labeled groups with a plurality of search results in each group; and generating a sub-grouping of search results for each labeled group of search results in the main grouping of search results using the second set of attributes.