Dewey Decimal Classification
Example Questions that can be answered by this FAQ:
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.
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.
However, OCLC does provide Summaries of the DDC down to the third level for free at:
You can also browse the top three DDC summaries in 9 languages at dewey.info.
The University of Illinois at Urbana-Champaign (UIUC) Library also provides the Summaries of the DDC down to the third level at:
You may also want to try out the Dewey Browser from OCLC, which lets you search or browse millions of records from OCLC's WorldCat database. DDC summaries down to the third level are provided as browsing links and for each result. Click the DDC number in a result to see them.
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.