Cataloging and Classification/Dewey Decimal Classification

The Dewey Decimal Classification system is named after Melvin Dewey, who created it in 1873. This system is widely used in public libraries, but in a few exceptions is also used in academic libraries.

Melvil Dewey 1891

Division fields

Dewey Decimal serves to organize library materials by their general knowledge field. Every DDC number contains three digits, similar to a MARC tag, but rather than describing the item itself, the DDC number describes what the item is generally about. The first number of the DDC tag represents its broad general field--is it about religion or geography?--while the second and third numbers represent more specific topics.

Number	Knowledge field
001-009	General knowledge
100-199	Philosophy and psychology
200-299	Religion
300-399	Social sciences
400-499	Languages
500-599	Science and mathematics
600-699	Technology
700-799	Arts and recreation
800-899	Literature
900-999	History and geography

Dewey classification resources

• The 20th edition of Dewey Decimal Classification (1989) is available online:
  • https://archive.org/details/deweydecimalcla01dewe
  • https://archive.org/details/deweydecimalcla02dewe
  • https://archive.org/details/deweydecimalcla03dewe
  • https://archive.org/details/deweydecimalcla04dewe