How to Use the Dewey Decimal System

Searching for a Specific Book

Search for your book in the library's card catalog. This system is likely computerized. If you are having trouble, ask a librarian for help or have her simply look it up for you. The Dewey Decimal System applies only to nonfiction books. This system organizes the books by topic, ranging from genetics to Victorian England to astrology. EXPERT TIP Kim Gillingham, MA Kim Gillingham, MA Master's Degree, Library Science, Kutztown University Kim Gillingham is a retired library and information specialist with over 30 years of experience. She has a Master's in Library Science from Kutztown University in Pennsylvania, and she managed the audiovisual department of the district library center in Montgomery County, Pennsylvania, for 12 years. She continues to do volunteer work for various libraries and lending library projects in her local community. Kim Gillingham, MA Kim Gillingham, MA Master's Degree, Library Science, Kutztown University Curious why the dewey decimal system exists? Kim Gillingham, retired librarian, tells us: "The Dewey Decimal system is a method for finding nonfiction books according to subject. You can use it to browse through the shelves by finding the number corresponding to your subject and looking for titles with the same number."

Obtain the call number contained in a book's entry. The call number will contain three digits or more. Record both the number and the author's last name before you begin your search.

Go to the shelves. Skim the spines of the books you pass to find the ones with the same first digit as your desired book. Then search those books for ones with the same second digit, and so on. Here's an example: Let's say you are looking for a book with Dewey Decimal number 319.21. Find the aisle that 319 would fall under, ignoring the decimals for now. For example, "300.2–340.99" would be the correct aisle, since 319 falls between 300 and 340. Walk down the shelf looking at the spines until you find the books beginning with 319. Search within the books beginning 319 to find the one you're looking for. These are arranged by the value of the decimal, so 319.21 falls between 319.20 and 319.22.

Look for a label matching both the call number and the author's last name. There may be multiple books with the same call number, so check the author's name to confirm that you've found the one you selected in the card catalog.

Browsing and Categorizing

Know the ten general areas of content. Melvil Dewey originally created ten general categories that most books could be sorted into. The ten areas are listed below with their corresponding numbers. 000 - Generalities, Computer Science, and Information 100 - Philosophy and Psychology 200 - Religion 300 - Social Sciences (anthropology, archeology, sociology) 400 - Language 500 - Natural Sciences (biology, astronomy, etc.) and Mathematics 600 - Technology (applied sciences) 700 - The Arts 800 - Literature and Rhetoric 900 - Geography and History

Understand divisions and sections. Each of the ten areas contain 99 divisions - more specific categories that fall under the larger areas. Additional decimals indicate the even even smaller sections, which are even more specific. Decimals are added if the topic is even more specific. An example of this specification process is below: 500 Natural Sciences and Mathematics 590 Zoology 595 Arthropods 595.7 Insects 595.78 Lepidoptera 595.789 Butterflies

Browse using the system. The Dewey Decimal System is great when you're browsing. If you wanted a book on Ethics, for example, you would go to 170. Once you were there you could scan the shelves for a book on an area of Ethics that interested you. This is infinitely more convenient than alphabetical arrangement, in which you might find a book on turtles next to one about turbulence in politics.

Look online to learn the categories. If your library is large and you would rather not spend a whole day browsing books on the Arts, you could go online for a guide to the various general categories, divisions, and sections. Websites with Dewey Decimal System guides include OCLC, The University of Illinois, IPL.