If you've looked up an item in Kemp Library, you'll notice that it's call number is a sequence of numbers followed by letters. Why? By assigning call numbers, we can shelve books on similar topics together. We use a classification system called the Dewey Decimal System to create those numbers.
The Dewey Decimal System is also called Dewey Decimal Classification, Dewey, and DDC.
Dewey Decimal Classification was created in 1876 by Melvil Dewey. Before the DDC was invented, libraries had items on the shelf in the order they were acquired, which could make it difficult to fine what you were looking for. Dewey Decimal Classification provides a structure for labeling items so that they will sit with items of the same or similar topics on the shelf.
Dewey has 10 broad classifications:
Each of these classifications serves as an umbrella, with many subtopics in each area. The longer the Dewey number, the more specific the subject is. For instance, works on comprehensive general science would be in 500, but if you wanted to look for Biology you would look in 570. Or if you were interested in all kinds of sports, indoor and outdoor, you would look in 790, but if you were interested in ball games you'd look in 796.3. and if you were interested in golf you'd look in 796.352. And then there are more specific numbers that build out from the golf number if you want to get very specific. By "build out", it means that you start with a basic number and add to it (build) to develop it's specificity. Here you can see we went from general sports, to ball sports, to golf - and with each subject, the number grew. Dewey numbers start in large general areas, and as the number gets longer, the more specific the subject gets.
The more numbers there are after a decimal in a call number, means that the number is highly specific. So the call number 813 is for general works of American fiction, 813.6 is American works of fiction published after 2000, and 816.609 is for historigraphical or critiques of American fiction published in 2000 or later.
So, when looking for a book, we recommend you also browse the shelves around that call number because you're likely to find many materials that will also interest you and be on topic.
If you would like a more detailed list of Dewey numbers, please visit the University of Illinois' page on Dewey numbers. You can also check out this excellent printable from the Central Institute of Technology.
Another example of how to read a call number can be found on the University of Illinois' website as well.
This is the label on the spine of a book that tells you where you can find the item in the library if you can read the code. The label is usually white with black lettering and is usually on the bottom of a book.
Here at Kemp Library we use Dewey Decimal Classification numbers combined with a Cutter Number. On the left is an explantaion of Cutter Numbers in "What's the 2nd Part of the Call Number?". Below is the explanation of Dewey Decimal.
Call numbers 000 - 199 are on the ground floor of the library (downstairs with the cow). Government Documents and the Curriculum Materials Center are also on the ground floor
Call numbers 200 - 999 are on the top floor (with the ships)
The first floor has the cafe, Reference and Circulation, microfilm, microfiche, periodicals and reference books