Classification
Arranging Library Resources
Libraries are organized to help users find the resources they need. Without classification and labeling of resources, users would have a hard time finding anything.
Imagine this: one night a mysterious alien force invades the library, removing all materials from the shelves, and replacing them so that all books, magazines, media, and a/v equipment are shelved together by size and color. The patron who always wants that small, red book will be happy, but everyone else will be wandering aimlessly through the shelves, seriously interfering with the SETI investigation of the alien force...
Libraries separate fiction (stories or novels) from non-fiction (true or factual information). The fiction may be separated into several genres (categories) such as mystery, science fiction, westerns, and others.
Non-fiction is usually classified - organized by a specific classification scheme. In public libraries this is most often the Dewey Decimal Classification (DDC) system. Classification places an item with other items on the same topic.
All copyright rights in the Dewey Decimal Classification system are owned by OCLC. Dewey, Dewey Decimal Classification, DDC, OCLC and WebDewey are registered trademarks of OCLC.
A place for everything
The DDC has 10 Main Classes. Each of those classes has 10 Divisions, and each Division has 10 Sections. (The Abridged DDC 14 is available for libraries with fewer than 20,000 titles.) The first digit in the Dewey Decimal Number is the main class, the second number is the division, and the third number is the section.
Get familiar with the Main Classes, at least. For example, history is in the 900s and science is the 600s. Then look at the Expanded Dewey table (the Hundred Divisions) from OLC's ORE on the Web reference training.
Monthly updates to the DDC are available on the OCLC site and via RSS feeds! For terminology questions, try the DDC glossary.
DDC First Summary - the Ten Main Classes
000 Computer science, information & general works
100 Philosophy & psychology
200 Religion
300 Social sciences
400 Language
500 Science
600 Technology
700 Arts & Recreation
800 Literature
900 History
You can download the DDC 22 Summaries (PDF format; 20 pages) for First Summary (the Ten Main Classes), Second Summary (the Hundred Divisions) and the Third Summary (the Thousand Sections).
What do the numbers mean?
Notation is the system of symbols (numbers, letters, etc.) used to represent the classes in a classification system. Classification provides a system for organizing knowledge. Classification may be used to organize knowledge represented in any form, e.g., books, documents, electronic resources.
The "notational heirarchy" for the DDC classification numbers 636.7 or 636.8 break down to:
600 Technology
630 Agriculture and related technologies
636 Animal husbandry
636.7 Dogs or
636.8 Cats
“Dogs” and “Cats” are more specific than “Animal
husbandry”; they are equally specific as each other;
and
“Animal husbandry” is less specific than “Dogs” and
“Cats.
[from the Dewey Summaries and Intro to Dewey, copyright OCLC]
Dewey on the Web
OCLC WebDewey "offers easy-to-use, World Wide Web-based access to the Dewey Decimal Classification (DDC) and related information, with searching and browsing capabilities," plus Library of Congress Subject Headings. A tutorial is available from OCLC. You can also take an animated tour of the DDC.
Library resources are classified so that they will be organized on shelves. Some libraries also organize online resources for users with the DDC. For example, the Webrary®, a service of the Morton Grove Public Library, consists of links to useful reference and information Web sites, organized by subject according to DDC classification. How does your library help users find Web sites on the same subject as materials in the library?
Urge to organize
Experts tell us that classifying stuff is a basic human instinct. Test this theory. Look around your home tonight. Would you say that (except for that one drawer full of junk) your kitchen is classified? How about your desk drawers? Closets? Your bookshelves? Would a map help? Would anything help!
What Now?
Complete the Activity, try the Explore section, and then go on to the next page: Call Numbers.
