Cataloging Policy and Procedure Manual
The Classification System
by Kendra Arrowood
Picture by John_Dewey_lib.jpg The Classification System
Books in the library are arranged on the shelves according to the Dewey Decimal Classification System (developed by Melville Dewey). This system, the most commonly used in school and public libraries, divides knowledge into ten different broad subject areas, called classes, numbered 000 - 999. Materials which are too general to belong to a specific group (encyclopedias, newspapers, magazines, library science, etc.) are placed in the 000's.
The Ten Main Classes of the "Dewey" System:
000 Generalities
100 Philosophy & Psychology
200 Religion
300 Social Sciences
400 Language
500 Natural Sciences & Mathematics
600 Technology (Applied Sciences,
including Medicine)
700 The Fine Arts
800 Literature & Rhetoric
900 Geography & History
SubclassesThe ten main classes are divided up into smaller classes by several sets of subclasses:
EXAMPLE:
500 - Pure Sciences & Mathematics
510 Mathematics
520 Astronomy & allied sciences
530 Physics
540 Chemistry
550 Earth Sciences
560 Paleontology, Paleozoology
570 Life Sciences
580 Botanical Sciences
590 Zoological Sciences
Specifying Subdivisions
Smaller divisions (to subdivide the topic even further) are created by expanding each subclass and adding decimals if necessary.
EXAMPLE:
520 Astronomy & allied sciences
523 Specific celestial bodies & phenomena
523.1 The universe
523.2 Solar system
523.3 The moon
523.4 Planets
523.41 Mercury
523.42 Venus
523.43 Mars
Before a book is placed on the shelves it is:
- Classified according to the subject matter it covers (given the Dewey number).
- Three letters are added to this number. This represents the author's last name or the first word of the title (if the book is edited with no one author).
- The number indicates where the book will be shelved in the library.