Understanding the Logic

In 1876 Melvil Dewey attempted to organized all human knowledge into 10 big, very general categories.
His plan was to find a way to put all the books that covered the same topic together on the library shelves.

STEP 1:

He assigned each of these categories a number from 000 to 900.
Books were assigned a number for a category based on their content.

STEP 2:

Dewey then divided each of these topics in 9 more specific categories.
He used a more precise number to identify the smaller categories.
This made 100 possible categories.
For example:

STEP 3:

Dewey then divided each of these smaller topics into 9 more specific categories.
He used an even more precise number to identify the even smaller categories.
This made 1000 possible categories.
For example:

STEP 4:

To create the possibility of more than 1000 categories, Dewey added the decimal point.
Now the number could be as precise a number as it needed to be to identify very, very specific categories.
For example:

IMPORTANT IDEAS TO UNDERSTAND

1. Dewey Decimal numbers are assigned to books using a HIERARCHY of ideas from general to specific. That means:
   
   • All big topics are divided into smaller topics.
     
   • All small topics are part of a bigger topic
     
2. Once you identify the number for a certain topic, all books with that number will be about the same topic.
3. This system makes sure that books on the same topic will be together on the library shelves because they all will have the same number.
4. If you are looking for information on playing chess, you would look for books with number 794.6 because that is the number for chess BUT you might also look for 794 which would contain information on all indoor games possibly including chess OR 794.64 which is just about chess openings. The numbers are related and so is the content of the books.

On to the next section... Locating a Book

Please send comments or questions to the 4J Web Team.
Eugene School District 4J
200 North Monroe Street, Eugene, Oregon 97402
Phone: 541.687.3123 [TTD 541.687.3447]

Last modified: October, 2003 by Steinke, Ague, Feuerhelm, Maxwell, and Warburg