The Alden Library organizes books according to the Library of Congress (LC) Classification System, sometimes called the LC System. Academic and research libraries use the LC System worldwide instead of the Dewey System, which is commonly used in high school libraries and public libraries. The LC System organizes books and other materials according to twenty-one major branches of knowledge. Each branch of knowledge is represented by one letter from the alphabet, excluding I, O, W, X and Y.

Each major branch of knowledge is further divided using a combination of letters and numbers. There are three parts to a LC "call number." For example, the book Classic Yoga by Vimla Lalvani is assigned the LC call number:

Librarians know that RA is the subclass of medicine that is used for public health, 781 stands for the topic "yoga" and L34 stands for the author's last name.

Think of the call number as the address of the book on the shelf and go to each section of the bookshelves in order:

1. Find the books labeled with RA. Books will be shelved in order by letter. For example:

2. When you have found all the RA's, look for the number:

3. Then look for the letter/number combination which follows:

The tricky part with this step is that you need to remember that the number on this line has a decimal so .L34 falls in this order:

The following is a row of books with LC call numbers shelved in the correct order:

George I. Alden Library, Quinsigamond Community College, 670 West Boylston St., Worcester, MA 01606 (508) 854-4366