What's the Dewey Decimal System all about, anyway?
Let's start with the basics. You know there are numbers, right? And decimals -- that's in the name. The numbers are grouped by 100's, with each section representing a major area of knowledge. The chart below gives you an idea of where, broadly, the information lives within the system.
Anatomy of a Dewey Decimal Number
OK, so the big numbers all mean something...but can you learn more from the rest of the number?
As you can see in the break-down below, the rest of the Dewey number can reveal more information about the item. The main number is called "the class" and is a very broad area of knowledge. The second number is a division number -- it narrows the focus of the very broad classification. The final number ahead of the period is the section number, which narrows the subject even further.
Many books will have numbers after the period as well. These are called "Cutter numbers" and give further information about the topic covered in the resource.
See below for a specific example:
So as you can see from this infographic:
- 900s cover history
- 970s cover North American history
- 973 covers US history
- and .921 lets you know that it's a biography!
You can search the Library & Information Center catalog here: