1. An information retrieval system, comprising: a plurality of files stored in memory, each defining a different hierarchical relationships of terms describing an organizational framework for information; a user interface which permits a user to select a level within each of at least two of the different hierarchical relationships; a search query generator responsive to the selection of the level within each of the at least two different hierarchical relationships to construct individual search queries of terms that are based upon the selected levels, and combine the individual search queries of terms to form a search query that is provided to a search engine, wherein the search engine searches a source of information to locate documents which correspond to the search query; and a display which displays information about the located documents to the user.