Today’s discussion of catalogues is about how you find things by topic. I talked about some of this in my post from March about personal libraries, but I want to talk more here about how libraries select subject terms.

It’s mysterious

Let’s be honest. A lot of the process librarians use to select subject terms is pretty mysterious. That’s because we’re trying to label quite complex things in a very complex world, and we’re using a variety of tools to do it, because outside of very very small collections (relatively speaking – in practice, this is probably a couple of thousand books at the smallest), it’s too big for anyone to keep in their head.

On the good side, this means people have to write things down, which makes long-term consistency easier, and which can help us see patterns.

On the bad side, it means things can feel (and be) very rigid, or slow to change, or complicated to navigate. All of which can make things a lot less accessible or useful. And the speed of change often means terms don’t reflect current understanding of things like identity, culture, or communities.

So where do these terms come from?

In libraries, libraries usually pick a set of subject headings to use. The subject headings act as a controlled vocabulary (which basically means ‘we have a fixed set of terms we choose from.) Like I explained in the post last March, this is what helps us avoid using all of these terms for the same thing:

• felines
• cats
• cat
• domesticated cat

Sometimes we might want to make distinctions (domestic cats as compared to lions or tigers or snow leopards), but if we don’t, we want to pick one term and settle on it.

Libraries use one of a couple of common lists for subject headings. The most common, probably, are the Library of Congress. These are very extensive (it takes up about 20 volumes as print books on a shelf) but the fact the Library of Congress deals with so many different topics means that it’s often quite slow to make adjustments.

For example, the addition of the word “Wicca” as a subject heading only took place in about 2004, and only after a petition from a librarian. (This is often the way changes get made: one or more librarians notice that a term needs adding or improving or changing, and they provide evidence.) The term ‘Wicca’ had been in broad general use since the 1950s and 60s, so that’s about 50 years.

This isn’t always simple – here’s a story of attempts in 2016 to get the terms ‘aliens’ and ‘illegal aliens’ changed, and how the support from librarians and library associations for a student-led project ran smack into issues of law.

(Why does Congress get a say in this, you might be wondering? The Library of Congress’s first job is to provide resources for Congress and members of Congress. Makes sense if you think about the name.)

One other important note is that many libraries don’t have the resources to go back and catalogue older items to the new subject headings – so you may see pointers from new terms to check older terms as well. (This depends a lot on the library and the priority of the topic.)

Who assigns the terms?

Good question. In many cases, the subject headings are primarily assigned by whoever it is at the Library of Congress assigns the headings for that particular item. These are likely people who have some experience in the general field or area of the books, but you can usually assume they’re not experts or specialists in all the nuances of the field or topic.

(In other words, they’re not going to get really nuanced about choosing, say, a term of magic or ritual in a Pagan setting. They may assign them both.)

Usually terms are based on the few most obvious and relevant topic. If something is mentioned for less than a chapter or two, it almost certainly won’t get a subject heading unless it’s something really unusual. For a full length nonfiction book, you can usually expect 3-5 subject headings.

You can also assume the person doing the cataloguing probably hasn’t read the book. Cataloguers don’t have time for that! They’re relying on the blurb on the back and things like skimming the table of contents. Publishers can also suggest subject headings or terms to include.

Some libraries do have their own cataloguers evaluate materials and add or edit terms. This is particularly true for things like local history or other items of particular local interest.

Or a school library might assign a heading for particular regular class assignments or projects, to make it easier to find those items. (There are other ways to group things, too.) Some libraries do a “Best resource” subject heading to make it easy to find the best resources in a topic. (Mine does this.)

Next week, more about working with search terms in practice.