A method and apparatus for searching for a documents residing on a network comprises receiving a search request from a user. The search request comprises one or more search terms of an ontology. The ontology includes a plurality of terms. One or more of the plurality of terms includes a plurality of sub-category terms. One or more documents residing on the network is identified based on the one or more search terms and an ontology index. The ontology index comprises a plurality of relationships between the plurality of terms and sub-category terms of the ontology and a plurality of documents residing on the network. One or more search results that describe the one or more documents is presented to the user. The one or more documents contain the one or more search terms, or one of the plurality of sub-category terms of the one or more search terms.