Last spring, the hashtag #ShowUsYourShelves trended on Twitter and Instagram, with people from all over the world proudly showing off their home collections. Organizing books by color, a trend that started several years ago, has once again resurfaced. There's no question about it—photos of rainbow-colored shelves are eye candy and pop on social media.

photo from Twitter user @RIBAginny

For some readers, organizing book by color—or size or date acquired—works. But bibliophiles seeking a more robust classification scheme for their beloved tomes may want to consider borrowing a few ideas from librarians.

The following is the first of a multipart weekly series designed to help readers make the most of their home collections. This week, we look at the traditional Dewey Decimal Classification system and how it might work for you. Future installments will tackle the pros and cons of “genrefying” fiction (separating distinct genres like romance, horror, sf/fantasy, etc.); how to “weed” your collection, including when to throw away or recycle outdated information; and how to best organize books for young children. Have a question for the librarian? Email us.

Before You Begin

Even before you start taking down titles from your shelves or tackling the books piled up on bedside tables, it’s important to decide what you want and need from your home collection. Begin by asking yourself (and the people who share your home) a few basic questions:

• How often do I refer to and need quick access to these books?
• Do I own enough books to make it worthwhile to develop a system for keeping them organized?
• Where will I put the books once I have them organized into distinct sections?
• Do I have enough shelf space to expand my collection as I acquire more books in the future?
• What subject areas or genres are my favorites that I may want to highlight in unique ways?

The most important consideration for any collection—in a studio apartment or a public library serving thousands of readers—is whether it serves the needs of its users. Whether you decide to go “full librarian” or simply devise your own classification system loosely based on broad subject areas, the key is to make it practical and useful for YOU.

Do You Dewey?

Think back to second or third grade; do you recall learning about the Dewey Decimal System? It is still the most widely used organization system for public libraries in the United States. It was developed back in 1876 by Melville Louis Kossuth "Melvil" Dewey, a librarian who founded the American Library Association (ALA) and this very publication, Library Journal. Before we delve into the details of his eponymous classification system, it’s worth pausing to reflect on the faults and biases of Dewey—both the man and the system.

While Dewey was a powerful and enthusiastic advocate for libraries, widely credited with helping create and shape the concept of the American public library, he was also well known even in his own time as a misogynist, sexual harasser, anti-Semite, and racist. Though he was an early supporter of women in librarianship—he was the first to propose that women be allowed entry into the library graduate program at Columbia College, where he served as head librarian—he did so because he believed women’s intellect and demeanor were uniquely suited to the “repetitiveness” of library work. There are numerous accounts of Dewey sexually harassing, groping, and forcing kisses and hugs on his female students and colleagues. In fact, his harassment of women was so reprehensible that the ALA forced him to step down as a leader in the organization in 1905. Dewey was also the founder of the Lake Placid Club, NY, where he wrote and enforced a policy banning Jews, black people, and “other religious and ethnic groups.”

This past June, the ALA decided to strip Dewey’s name from its top professional honor, the Melvil Dewey Medal, in recognition of his history of racism, sexual harassment, and anti-Semitism.

It’s likely not surprising, then, that Dewey’s own prejudices manifest themselves in the library classification system he invented. While it remains the most popular and recognizable way public librarians organize books, it’s worth noting that even professional librarians and catalogers adjust or ignore certain elements of his system. Indeed, it is useful to remember that any classification system is a reflection of the values, beliefs, and, yes, biases of its creator.

DDC 101

Nonetheless, the basic structure of Dewey classification may provide a good starting-point for shelf organization, particularly for nonfiction, informational books.

Here’s how it works: all information is organized into ten main classes by subject, discipline, or field of study, identified by a three-digit number:

000 —General Information, Computer Science

100 —Philosophy & Psychology

200 —Religion

300 —Social Sciences

400 —Language

500 —Science

600 —Technology

700 —Arts & Recreation

800 —Literature

900 —History & Geography

Those categories are likely broad enough to start creating piles of the books in your home. This may be all you need to start organizing your shelves. You could start by looking at each title in your collection and determining which of the ten classes it fits into. For example, Truman Capote's true crime classic, In Cold Blood, would fall under the 300s (social sciences); Stephen Hawking's A Brief History of Time would fall under the 500s (science); and The Complete Collected Poems of Maya Angelou would fall under the 800s (literature).

Once you've grouped similar books together, consider separating the sections on your bookshelves with bookends, paperweights, or homemade objets d’art.

Folks with very large collections—and lucky enough to have the shelf space to display them—can go even deeper and get more specific with classification. Each of the ten main classes is further divided into ten sections. Take the 500s for example:

500 —General works on science, math, or natural history

510 —Math

520 —Astronomy

530 —Physics

540 —Chemistry

550 —Earth Science & Geology

560 —Fossils & Prehistory

570 —Biology

580 —Plants

590 —Animals

Using the above title examples, Truman Capote's In Cold Blood would get a 360 classification number ("social problems"); Stephen Hawking's A Brief History of Time goes with the 520s (astronomy); and Maya Angelou's collected poems goes under 811 (poetry).

Within those secondary classes are further classes that get even more specific. For example, 592 is the DDC number reserved for books about invertebrates while 599 is for mammals.

While you’re unlikely to need such specific classification for the books in your home, it can be fun to take a deep dive into the classes and figure out what works best for the books you own.

Are you a history nerd with a huge collection of history books? It might be helpful to take a look at the 900 section, which reserves 930 for books on the ancient world; 940 for European history; 950 for Asian history, which includes South Asia and the Middle East; 960 for African history; 970 for North American history, with973 reserved for histories of the United States; 980 for South American history; and 990 for Australia, New Zealand, New Guinea, Polynesia, and Antarctica.

Note that not all DDC classes are created equal. The 200s, for example, the classification for religion, devotes almost all of its sections to Christianity, reserving only the 290s to "all other religions." For many years, books about LGBTQ topics were relegated to the section on abnormal psychology. And books about women were for a long time shelved with works on home economics and etiquette. As Hope Olson explained in her 2002 work, The Power To Name: Locating the Limits of Subject Representation in Libraries , classification schemes have a tendency to "marginalize and exclude Others" and center the perspective of a "white, male, Eurocentric, Christocentic, heterosexual, able-bodied, bourgeois mainstream."

It is for this reason that any organization system you select should prioritize human considerations. There is no right or wrong way to organize the books in your home. You may find, as you start pulling books off the shelf and reflecting on their meaning to you, that DDC is not the right fit. You may find better inspiration in how the Library of Congress organizes its many, many volumes. Or you might want to emulate your favorite indie bookstore and go with BISAC-inspired shelves.

Libraries and archives with hundreds and thousands of titles don't just rely on shelf organization; a catalog allows users to determine the exact shelf location of any given book. Readers of a certain age may remember thumbing through the old card catalogs filled with index cards that contained the information for every title in a collection. These days, catalogs are largely online and users can search by keywords. For truly ambitious home librarians interested in taking their book organization to the next level, creating a spreadsheet to catalog titles or using an online database like LibraryThing might be worthwhile longterm project.

However you decide to organize your books, we'd love to hear about it—and see photos of your progress!