From Big Medical Encyclopedia

DESCRIPTOR (Latin descriptor describing) — the word or the phrase serving for the description of the main semantic contents of documents, and also for the formulation of queries by search of documents in to the information retrieval system (see). To each D. there corresponds the class of documents in which it occurs; its corresponds to each document «a search image» — the list D. reflecting the basic concepts which are contained in the document. All D.' list of this information retrieval system (IRS) forms its dictionary. The obligatory requirement to the dictionary is lack in it of synonyms, homonyms and polysemanticism (i.e. polysemies). The request for search of the documents containing the necessary information forms in the form of logical function from descriptors of the INFORMATION RETRIEVAL SYSTEM. E.g., if the dictionary contains D. «liver» and «tumors», then on a request «the liver and tumors» will be given all documents containing both D., i.e. generally documents on tumors of a liver, and on a request «a liver or tumors» — all documents containing at least one of these. The dictionary D. and ways of formation of search images and requests for search form descriptor language. The INFORMATION RETRIEVAL SYSTEM based on descriptor language is called descriptor. Descriptor INFORMATION RETRIEVAL SYSTEMS are more flexible, than the traditional systems of the organization of help fund leaning on the universal decimal classification (UDC) and gain ground, especially in the automated INFORMATION RETRIEVAL SYSTEMS.

Bibliography: Zakharov V. N., Pospelov D. A. and Hazatsky V. B. Control systems, task, design, implementation, M., 1972, bibliogr.; Mikhaylov A. I., Black A. I. and Gilyarevsky R. S. Fundamentals of information science, M., 1968, bibliogr.

O. P. Kuznetsov.