How the Dewey Decimal System Works
The Dewey Decimal Classification system is the one most often used in school and public libraries to organize books on the shelf into subject groupings.
It is a hierarchical classification system that starts by dividing knowledge into ten broad categories
|
000 General
Knowledge |
500
Sciences & mathematics |
You could also think of these categories in terms of the kinds of questions that they answer (as Melvil Dewey, the inventor of the system did)
Each category gets subdivided, again and again, into more and more specific areas of knowledge. As this happens the call numbers grow longer, and decimal points are added. The more numbers to the right of the decimal, the more specific the subject is.
500 Natural sciences & mathematics
590 Zoological sciences
598 Birds
598.9 Birds of prey
598.97 Owls
Since there's probably more than one book about owls, we add the first two letters of the author's last name and the first letter(s) of the title, to identify a particular book.
598.97 MAO is a book called Owls by Sandra Markle
This differs slightly in the fiction and picture book areas, where there are thousands of books with the call number 823. Instead of just using just the first letters of the author's last name, a combination of letters and numbers keeps the books in strict alphabetical order.
823 L723S FIC Shutterbug follies by Jason Little
823 L724B7 FIC Brothers far from home by Jean Little
Here's more about using the call number to find your book on the shelf; or go to the Collections page for advice about how to narrow your search to specific kinds of materials (picture books, video materials, posters etc).