SAPHIRE--an information retrieval system featuring concept matching, automatic indexing, probabilistic retrieval, and hierarchical relationships

SAPHIRE (Semantic and Probabilistic Heuristic Information Retrieval Environment) is an experimental computer program designed to test new techniques in automated information retrieval in the biomedical domain. A main feature of the program is a concept-finding algorithm that processes free text to find canonical concepts. The algorithm is designed to handle a wide variety of synonyms and convert them to canonical form. This allows natural language to be used for query input and also serves as the basis for a new approach to automatic indexing based on a combination of probabilistic and linguistic methods.