(DDC) A hierarchical system for classifying books and other library materials by subject, first published in 1876 by the librarian and educator Melvil Dewey, who divided human knowledge into 10 main classes, each of which is divided into 10 divisions, and so on. In Dewey Decimal call numbers, arabic numerals and decimal fractions are used in the class notation (example: 996.9) and an alphanumeric book number is added to subarrange works of the same classification by author and by title and edition (996.9 B3262h). Click here to see a list of DDC summaries. Developed and updated continuously for the past 125 years, most recently by a 10-member international Editorial Policy Committee (EPC), DDC is the most widely used classification system in the world. According to OCLC, it has been translated into 30 languages and is used by 200,000 libraries in 135 countries. The national bibliographies of 60 countries are organized according to DDC. In the United States, public and school libraries use DDC, but most academic and research libraries use Library of Congress Classification (LCC) because it is more hospitable. The abridged edition (ADC), intended for general collections of 20,000 or fewer titles, is a logical truncation of the notational and structural hierarchy of the full edition. OCLC has also developed WebDewey for classifying Web pages and other electronic resources. Click here to connect to the DDC Web site maintained by OCLC and here to read OCLC's Introduction to Dewey Decimal Classification. See also: Universal Decimal Classification.


From ODLIS, Online Dictionary for Libary and Information Science by Joan M. Reitz
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