Dewey Decimal Classification

Example Questions that can be answered by this FARQ:

• Is there a complete listing of the entire Dewey Decimal Classification online?
• How can I set up my small library with the Dewey Decimal system?
• Is there a web site where I can enter a book’s title and get its Dewey Decimal number?

The Dewey Decimal Classification system (DDC) has been used for over 100 years in libraries around the world to organize books so that books that are on the same subject are near each other on the shelves. IPL patrons often ask us for help when they want to organize their libraries using Dewey Classification numbers, or need to find Dewey numbers for books they want to add to an existing collection.

The DDC is published by OCLC Online Computer Library Center, Inc. OCLC does NOT make a complete listing of the Dewey Decimal Classification available online for free. Their Dewey Decimal Classification Home Page provides information about the products that you can purchase from them, including WebDewey, their commercial online product.

However, OCLC does provide Summaries of the DDC down to the third level for free at:

http://www.lib.colum.edu/library/deweysum.html

The University of Illinois at Urbana-Champagne (UIUC) Libary also provides the Summaries of the DDC down to the third level at:

http://www.library.uiuc.edu/library/circ/tutorial/dewey-schedule-numerical.html

Smaller libraries may find that this level of detail is all that they need to organize their libraries. Larger libraries will probably find that they need to buy a new or used copy of the multi-volume DDC or subscribe to WebDewey in order to organize their collections effectively.

A short-cut that many libraries use when they have a book that they need a Dewey number for is to see if they can find another library that has already assigned a Dewey number to the book. A good place to check first is the Library of Congress’ online catalog, because their collection is so large and their records also include Dewey numbers. If you go to this web page on their site:

http://catalog.loc.gov/

You can see the various ways available to search their online catalog.

If the above resources do not answer your question about the Dewey Decimal system, you may want to ask your question on AUTOCAT , an electronic discussion list for catalogers.