Proposes a model of knowledge-based information retrieval (KBIR) that is based on a hierarchical concept graph (HCG) which shows relationships between index terms and constitutes a hierarchical thesaurus as a knowledge base. Conceptual distance between a query and an object is discussed and the use of Boolean operators is described. (25…

Proposes that topic representations should consist of excerpts from domain thesaurus, generated by spreading activation technique. Algorithm for generating excerpts is outlined and exemplified, and problem of assessing resemblance between two excerpts is discussed. Whether existing thesauri are adequate for this purpose is questioned, and ideas…