Monthly Archives: June 2015

Don’t Catalog a Book by its Cover

This is Matt Croydon and you are listening to The Tinycast.

Libraries have books. A lot of books. Librarians need to know where to put them and the general public needs to know where to find them. This has been a problem in need of a solution since before the existence of books themselves.

If you had asked me how to catalog non-fiction books when I was in 5th or 6th grade, I would have told you emphatically that there was only one way: the Dewey Decimal System. The Dewey Decimal System dominates the library catalog scene — at least in the United States — at the elementary and public library levels. It’s what I encountered at school and when I hung out at the public library.

One of the things that makes the Dewey Decimal System so great is that it does an efficient job at conveying a lot about the subject of a book with just three numerals, and decimals allow librarians to be specific. This also helps define an exact way that books should be ordered on the shelf.

Zero starts off with general works, computer science, and other general information. This is often the dark corner of the library where you’ll find me. 100 is Philosophy and Psychology, which includes a lot of crazy paranormal and occult stuff around 130. 200 is religion, 300 is the social sciences, statistics, political science, economics, law, education, and even some communication and transportation stuff. 400 is Language, including linguistics and information about individual languages. 500 is science, math, astronomy, physics, chemistry, biology, and a bunch of other stuff. This was another well-traveled section of the library for me. 600 is technology (another favorite), medicine, engineering, manufacturing, and a bunch of stuff for the home: cookbooks, home repairs, and childcare. 700 is arts and recreation, architecture, design, painting, photography, music and sports. 800 is literature; 900 is history and geography.

The second and third numeral in a Dewey decimal are more specific. For example, let’s consider The Wright Brothers by David McCullough. It’s in six hundred (Technology) twenty (Engineering) nine (other branches of engineering). I can’t actually tell you what the decimals .1300922 mean. The Dewey Decimal system, or Dewey decimal classification and relative index, as it’s called, is actually a copyrighted and proprietary work. The closest copy to me is at the University of Texas Austin, and interestingly enough, doesn’t bear a Dewey decimal number on its spine.

Most university libraries — in the United States at least — use another major system called the Library of Congress Classification. This system has been around a long time but is newer than the one designed by Melvil Dewey in 1876. It was designed by Herbert Putnam in 1897 and actually borrowed a lot of ideas from Charles Cutter‘s Expansive Classification System, one that never really caught on.

The LCC uses the letters A through Z for its major classification. The Wright Brothers book can be found under TL (Motor vehicles, Aeronautics, and Astronautics) 540 (in the section for Aeronautics. Aeronautical engineering).

Both classification systems actually use additional information about the subject, title or author to arrive at a complete and unique identifier for a book. For example the LCC for The Wright Brothers includes W7 (the Cutter encoded value for Wr, short for Wright) M3825 (the Cutter encoded author name) 2015 (the publication year). I’ve seen Cutter encoded author names and publication years on Dewey spines as well.

There are other ways to catalog books too. Fiction is often organized by author name within a large classification: children’s, classics, science fiction, young adult, fantasy, you name it. Biographies are sometimes arranged by their subject, but they’re often sprinkled about the rest of non-fiction as well.

Each region and country around the world has its own dominant catalog system, as well as a rich history of other systems that have come and gone. Here’s a quick sampling for you: The Resource Description and Access system appears to be replacing the Anglo-American Cataloguing Rules, 2nd Edition at the university level in the UK, though Dewey still dominates public libraries there. Sweden has a letter based system called the SAB (Sveriges Allmänna Biblioteksförening), and the Nippon Decimal Classification and Korean Decimal Classification systems are similar to their Dewey ancestors. The Chinese Library Classification is the result of thousands of years of refinement. Seriously, you could get lost on the internet or in a library for days reading about this stuff.

In the end though, library classification systems throughout the world have more in common than they have differences. Dewey’s big trick is being able to sort books into broad categories based on that first numeral, but once you get used to it the letter-based systems do the same thing, just with more buckets.

The title of this podcast is The Tinycast. The author is Matt Croydon.

Music for today’s show includes Odyssey and Marty Gots a Plan by Kevin Macleod. You can hear more at This episode also features Lullaby for a Broken Circuit by Andy Miccolis a.k.a. Quiet Music for Tiny Robots. You can find him at

Check out where you’ll find lots of links and information to stuff I couldn’t cover in a single episode. See also twitter @thetinycast, You can find us at Dewey Decimal 006.7876, LCC TK 5105, and at podcast libraries everywhere. You’ll find me on Twitter, @mc. Episodes are also available at the Public Radio Exchange,

Further Reading

Additional Music Info

“Odyssey” Kevin MacLeod (
Licensed under Creative Commons: By Attribution 3.0

“Marty Gots a Plan” Kevin MacLeod (
Licensed under Creative Commons: By Attribution 3.0

“Lullaby for a Broken Circuit” Quiet Music for Tiny Robots (
Licensed under Creative Commons: By Attribution 4.0