Just "Dew" It: A Crash Course on the Dewey Decimal System

by West Bend Library on 2019-06-21 12:00:00

If you don’t know anything about the Dewey Decimal System, trying to find a book at the library can feel like a maze of meaningless numbers. But if you familiarize yourself with the system, finding what you need will become a whole lot easier.

The Dewey Decimal system is no new invention; in fact, it’s been around since 1876, just a year after the Civil War ended. It was created by American librarian and educator Melvil Dewey, who worked in multiple libraries throughout his life. Frustrated by the organizational inconsistencies in these libraries, he decided to design his own method of categorization, assigning numbers to books based on their subject. Shortly after its creation, this new system became widely popular and was adopted in libraries across the country. Today, 200,000 libraries in 135 countries use the Dewey Decimal System. Although its popularity has endured, the system itself has changed significantly over the years; for example, racially insensitive subcategories were removed or renamed, and new categories were added. The system continues to change even today; new hard-copy editions of the Dewey Decimal Classification books are released periodically, and the online database known as WebDewey is modified quarterly.

Though widely used and constantly changing, the Dewey Decimal System is not an ideal classification system. Not only was its creator racist and misogynistic, but the system itself causes many practical issues. For instance, it places books on similar subjects in drastically different areas of the library, and it usually isn’t used to organize fiction books. Moreover, problems arise when one book has multiple themes; though the original goal of the Dewey Decimal System was to universalize library organization, it leaves excessive room for interpretation.

Nevertheless, the Dewey Decimal System can be very helpful. After all, it’s used in most libraries throughout the English-speaking world, so if you have a rough grasp on the main categories in the system, it’ll be easier to navigate your local library and others across the country. At the West Bend Library, there are two main non-fiction sections: the children’s non-fiction area on the first floor, and the adult non-fiction section, which spans the entirety of the second floor. Smaller areas of non-fiction materials, such as audiobooks, DVDs, and large print books, can be found in the library as well. To clarify, only non-fiction materials are classified with the Dewey Decimal System in our library. Fiction books, on the other hand, are simply alphabetized by the author’s surname and sorted by genre (the adult mysteries have their own special section) or by reading level (in the children’s fiction).

The Dewey Decimal System uses these ten main categories to classify materials:

000-099: General Works. In this section, you will find almanacs, encyclopedias, manuscripts, news media, record books, and computer science materials.

100-199: Philosophy. This category holds works on philosophy, logic, ethics, astrology, and the paranormal. It also contains materials about the self, feelings, dreams, and psychology.

200-299: Religion. Here, you will find materials concerning world religions such as Christianity, Judaism, Buddhism, Hinduism, and Islam, as well as mythology.

300-399: Social Science. Materials about sociology, anthropology, political science, education, and law can be found in this section, right alongside folklore and fairy tales.

400-499: Languages. This section is designed for those learning Spanish, French, German, Italian, and other foreign languages. It also contains materials on linguistics, classical languages, and English as a second language.

500-599: Natural Science. The materials found in this section concern astronomy, physics, chemistry, geology, biology, botany, and zoology.

600-699: Applied Science. Technology, engineering, agriculture, management, manufacturing, and construction materials are located in this section.  

700-799: Arts and Recreation. Between 700 and 799, you’ll find materials on architecture, ceramics, painting, graphic art, music, sports, and entertainment.

800-899: Literature. Separated from the main fiction areas of the library, this section holds plays, poetry, joke books, and literature analyses.

900-999: Geography and History. The last main section includes materials on genealogy, geography, and travel, as well as atlases and historical books on various areas of the world.

These ten main sections are divided into many (many, many, many) subsections. For example, the 500’s focus on natural science.  Within this category, there are many subcategories; 510-519 corresponds to mathematics, 520-529 to astronomy, 530-539 to physics, and so on. These subcategories can be divided even further into individual numbers. For instance, 570-579 focuses on biology; 571 is about physiology, 572 is about biochemistry, and so forth. Even these individual numbers can be broken down into further subcategories using decimals (hence the name, Dewey Decimal System.)

So if you were looking for a book on tigers, you’d look for the 500’s section, which concerns natural science. Within this section, you’d look for the 590’s, which focuses on zoology. Within the 590’s, you’d look for 599, which is specifically about mammals. Within 599, you’d look for 599.7, which concerns carnivorous mammals. Finally, you’d find 599.756, which is the call number specifically referencing tigers. These numbers can be found on the spine of each library book. The top numbers are the same at every library using the Dewey Decimal System; the call numbers below that are unique to our library. Understandably, there are thousands of subcategories. The picture above features the West Bend Library’s four Dewey Decimal Classification “bibles,” which list all of the current categories in the system.

Feeling overwhelmed yet? Thankfully, you don’t have to memorize hundreds of subcategories to find your way around the library; just remember the ten main categories. Once you get familiar with them, it’ll be much easier to find the materials you need. Additionally, there are many simple ways to find a book at the West Bend Library that don’t involve any memorization at all. For instance, there are five public catalog computers on the first floor and two on the second that can be used to find call numbers. There are also informational brochures available on each floor, and reference posters in the children’s non-fiction section.

Alternately, you could use Monarch, our online catalog, to find a book’s location in the library. To do so, simply look up the book you want to locate, and click “find it” to discover the book’s call number. If all else fails, one of our librarians will be happy to help you find any book you’re looking for.

Hopefully, by familiarizing yourself with the basic concept of the Dewey Decimal System and the ten main categories it utilizes, you’ll be able to navigate our library (and any other library you might come across) more effectively. Next time you’re looking for a book, put your new knowledge into practice. You can “dew” it.


Ainsworth, Colin. “5 Controversial Facts About Melvil Dewey and the Dewey Decimal System.” Mental Floss, Mental Floss, 10 Dec. 2018, mentalfloss.com/article/566704/melvil-dewey-decimal-system-controversies-facts.

“Monroe County Public Library, Indiana.” Monroe County Public Library, Indiana, Monroe County Public Library, Indiana, 19AD, .

Watson, Samantha, and Hannah Kane. “Interview with Teen Librarian about the Dewey Decimal System in the West Bend Library.” 18 June 2019.