What are the sparse and overcrowded areas of Dewey Decimal System?

Here’s a question for all the librarians:

While I was wandering the stacks this weekend at the local library, I couldn’t help but notice that the Dewey Decimal System is pretty uneven in parts. There was a whole stack of shelves devoted to one four decimal-place call number, 364.1524. On the other hand, I was looking for a book with 022.4, and there wasn’t a single item in 022. I suppose the books that people were interested in just weren’t the same ones that Mr. Dewey expected.

So what are the areas that make librarians gnash their teeth because of the overcrowding? Which need barely any shelves at all? And does this also happen in the Library of Congress system?

I used to shelve books in a university library.

The 0’s tend to have a lot of blank spaces, and parts of the 100’s as well. The 200’s are for all religious books, but spaces from 200 up to 290 (or so) are for books about Christianity, so there’s usually some space there, especially in the sections on the early Chruch and other scholarly esoterica. The other areas are pretty well filled up, except for the 880’s (Latin and Greek literature).

Sorry to hijack, but I always wondered something. Will a book have the same decimal number everywhere? Is a book assigned a specific number, or does it vary on library or system of libraries? Also, if they are the same universally - who assigns the numbers? Do other countries use the DDS?

It’s important to note when your classification system was devised and the developments in scholarship and human endeavor since then - women’s studies is EXTREMELY crammed into (IIRQ) the HQs in the LC system, as is queer theory, because these just weren’t big book-producing subjects when this was all put together. I work in a business library, and shelf-reading the management books, the diversity in the workplace books, that sort of thing - it’s miserable.

Bear - in response to your hijack, as far as I know, each library has the option of assigning its own Dewey decimal number to an item. There is usually a suggested number inside the book, on the page with the title, author, subject, etc … I believe there’s also an LC (Library of Congress) number there as well.

But each library has the option of using that number, or using a number that fits in with its own system. Of course the basic rules must be followed, but they have a bit of leeway on the number extension (the numbers after the decimal). Many smaller, general libraries use the suggested number. More specialized or larger libraries will assign their own.

Sorry for the vagueness of my reply - I’m actually a library technician but my course was a LOOOONG time ago, and I haven’t stayed in the field.

The DDC varies between libraries. It just depends upon what the cataloging department wants to use.

The gaps exist because the numbers were set up a long time ago and really haven’t been adjusted to the 21st century.

The religion section 200 reserves 200-289 for Christianity. All the “rest” go into 290-299.

Another section that is quite empty in most libraries is the 400 section.

In my library, I am responsible for collection development in 658-659 (marketing and advertising). It’s about 12 AISLES of books.

The Dewey Decimal System, now in its 22nd edition, is administered by the OCLC (Online Computer Library Center), a worldwide consortium of libraries founded in 1967. Their website says,

Most books published in the U.S. today already have the DDS number (and the Library of Congress System number) printed on the copyright page. But any library is free to assign a more precise number, or even a different number, as it chooses. Classifying books under the DDS is an art, not quite a science.

I’m not a librarian, but I’ve worked as a page at a library for several years.

The biggest sections at my library are those on cooking, home decorating, and travel. The 400s are sparse (these are books on language, spelling, etc.) The 100s are mostly dedicated to computer books, though this classification also includes books on psychology, the supernatural, other general interest matters. There are a number of places, particularly in the 600s, where the numbers jump from one crowded section to another, leaving numbers of specialty books behind.

The Dewey number can indeed vary. Interestingly, books with long numbers can have truncated numbers sometimes. Often, specialized books (for instance, a book on hiking trails for the disabled in Boulder, CO), will have lengthy numbers, but the copyright page will delineate the places where the code can be truncated.

Sure, in a public library, the 200’s (Religion) will be sparse. But at Catholic colleges, there are stacks and stacks of 200s going to the fourth or fifth decimal place.

So, it all depends on the type of collection a particular library has.


Computer books in the 100s? Huh? That’s the Philosophy section?

Computer books usually end up in the 001s in newer libraries.

What book were you in?

Even or odd?

Must have been a lot of turnover.

How many nembers can there be after the decimal?

My favorite example of why a library might choose a different number than given by the publisher: Many books on fringe subjects (occult, UFOs, crypto-history, etc.) may be given numbers by publishers that suggest they are “serious” books of a scientific/professional nature. Many librarians are smart enough to not fall for that. Since it is up to the individual library, it makes it hard to sue a bunch of nice LOLs (stereotype-wise) vs. a central assignment center. You can also notice the difference in categorization at many bookstores.

There can be as many numbers after the decimal as needed. I don’t recall seeing more than 8.

The Los Angeles Public Library puts books on Bigfoot and the Loch Ness Monster in the zoology section (590s). And books on UFOs are in mechanical engineering (629). Books on Atlantis are in History.

Most of them were in the 001s, but there are a few in the early 100s - the more generalized ones, I think. Maybe there’s been a labelling mistake or something, I oughta check that out, because now that you mention this, I haven’t seen things done that way at any other library.

In my local library, computer “application” books are shelved sep. from Computer Science-ish books. There is a difference. We Computer Scientists don’t research MS Word all day. It’s like Math vs. Accounting. But I don’t recall the DDS numbers. (Just position, but then they renovated last summer…)

This is probably not relevant, but as you can imagine, specialized libraries are very heavy on one or two sections. I used to work as a clerk in my university’s law library; the J and K sections of the LoC classification took up most of two floors.

When I worked at the library at Cooper Union (when I was a student there…), the 700s (arts/architecture, I believe) took up their own room (well, bay) - we were converting from Dewey to Library of congress at the time (late 80s - 1990), and of course the 700s were slowly being converted into their LoC numbers (which also took up it’s own bay - dang, forgot the 2 LC letter code for Art - I could look it up, I guess)
The technology section was a surprising moderate size for a heavy engineering school (one of the big three: Art [including Graphic Art, and the heavily mocked Corporate Art], Architecture, Engineering - RA!). This was before the tremendous explosion in Computer books during the '90s, when seemingly anyone who had access to a word processing program cranked out computer book after computer book after computer book (I remember when Barnes & Noble had 10 full shelve sections of computer books…now they’re down to 4) :frowning:

780.92 (music history - biographical) managed to take up two aisles where I studied, with the whole floor dedicated to half the 700s…great apart from when something got mis-shelved…