Databases and public access catalogs are being used extensively by the public and the academic and business communities as major sources of information. Most users want to access these databases directly to locate the information they need. Increasingly, users are demanding user-friendly databases that will assist them in finding conceptual information effectively. The lack of compatibility or standardization among many different indexing vocabularies and thesauri makes it difficult to find related information in information retrieval systems containing many different online databases....