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Understanding Call Numbers: Dewey Decimal Classification System (Dewey)

This guide is to help understand how call numbers help are used to organize materials.

Northwest Georgia Regional Library

Dalton State Roberts Library is not the only library in town.  You can also use your local community libraries.  

Most Public Libraries in Georgia can be accessed by using PINES. Georgia Library PINES (Public Information Network for Electronic Services) is the public library automation and lending network for more than 275 libraries. PINES creates a statewide "borderless library" that provides equal access to information for all Georgians.

You can access them by going to the Northwest Georgia Regional Library at the site below. Be sure and select the library that is close to you.

Mevil Dewey

Dewey Decimal Classification System

The Dewey Decimal Classification System is subject based, classifying and arranging items by the subject matter involved. Roberts Library does not use Dewey call numbers.

  • Dewey call numbers begin with a three digit number

             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 & geography

  • The Dewey system further breaks these subjects into subclasses by the addition of the next two digits, and then often even adding a decimal point and more numerical digits. For example:

               500 Dewey call numbers deal with Natural Sciences & Mathematics

               590 Dewey call numbers deal with Zoological Sciences

               599 Dewey call numbers deal with Animals

               599.884 Dewey call numbers deal with Gorilla Behavior


For a list of the major classes and subclasses of the Dewey Decimal classification system, click on the following link and scroll down:

  •  The second part of a Dewey call number is based on the Author's last name.

                  Some libraries use only the author's name, or the first letters of the author's name. For example, the call number for Gorillas in the Mist, by Dian Fossey would be: 599.884 FOS

                  Some libraries use the first letter, or letters of the author's name followed by numbers representing the author and the particular item. 
In this case, the call number for Gorillas in the Mist is: 599.884 F752g


  • Frequently a Dewey call number will include a third part which represents the year that the item, or particular issue of an item, is published.  Again, the call number for Gorillas in the Mist599.884 F752g 1983

Melvil Dewey

The Dewey Decimal System (Dewey or DDC) was conceived by Melvil Dewey in 1873 and first published in 1876. 

Melville Louis Kossuth Dewey was born on December 10, 1851 to a poor family who lived in a small town in upper New York state. Keenly interested in simplified spelling, he shortened his first name to Melvil as a young adult, dropped his middle names and, for a short time, even spelled his last name as Dui.

Dewey invented the Dewey Decimal Classification (DDC) system when he was 21 and working as a student assistant in the library of Amherst College. His work created a revolution in library science and set in motion a new era of librarianship. Melvil Dewey well deserves the title of “Father of Modern Librarianship.”

Dewey changed librarianship from a vocation to a modern profession. He helped establish the American Library Association (ALA) in 1876; he was its secretary from 1876-1890 and its president for the 1890/1891 and 1892/1893 terms. He also co-founded and edited Library Journal. In addition, Dewey promoted library standards and formed a company to sell library supplies, which eventually became the Library Bureau company of today.

A pioneer in library education, Dewey became the librarian of Columbia College (now Columbia University) in New York City in 1883, and founded the world’s first library school there in 1887. In 1889, he became director of the New York State Library in Albany, a position he held until 1906.

Melvil Dewey died after suffering a stroke on December 26, 1931 at age 80. Seven decades after his death, he is still primarily known for the Dewey Decimal Classification, the most widely used library classification scheme in the world.

Taken from "How one library pioneer profoundly influenced modern librarianship" at