Current information retrieval systems focus on the use of keywords to respond to user queries. We propose the additional use of surface level knowledge in order to improve the accuracy of information retrieval. Our approach is based on the database concept of semantic modeling (particularly entities and relationships among entities). We extend the concept of query-document similarity by recognizing basic entity properties (attributes) which appear in text. We also extend query-document similarity using the linguistic concept of thematic roles. Thematic roles allow us to recognize relationship properties which appear in text. We include several examples to illustrate our approach. Test results which support our approach are reported. The test results concern searching documents and using their contents to perform the intelligent task of answering a question.