Subject vs. Keyword

You may recall a previous post in which I mentioned that I'd use an entry to explain what, exactly, the difference is between keywords and subjects. The distinction is not an intuitive one, but it's an important distinction just the same, one that will vastly change what kind of results you'll get in the Catalog searches that you do.


When you're doing a search on The Catalog, you'll notice that you are given four options to search by: Keyword, Title, Author, and Subject. Two of them are pretty self-explanatory:

• Author: make sure you're putting the author's last name first, as in "King, Stephen"

• Title: omit any initial articles that may be in the title; so that A Tree Grows in Brooklyn becomes "Tree Grows in Brooklyn"

The other two options, Keyword and Subject, seem redundant at first glance. After all, one dictionary definition for "Keyword" is "a word used to describe the contents of a document," which is arguably a pretty good definition for "Subject," too. The important thing to keep in mind is that, when it comes to searching online in The Catalog, on databases, and through archives, "Subject" and "Keyword" almost always mean two very different things.

Let's look at a "Subject" search first. You may have noticed, when you look at the main page of any library item, that nearly all items have a list at the bottom, under the "Details" section of the page, that list subject headings. For instance, if I were to look up Eliot Asinof's Black Sox baseball classic Eight Men Out:

I get this list of subject headings at the bottom of the page:

Since this book is the true account of the eight White Sox ballplayers who threw the 1919 World Series, the subject headings make sense. But the subject headings are there to do more than describe the contents of this particular book -- they're also there to guide you to other books on similar topics.

If you click on the underlined link reading "Chicago White Sox (Baseball team) -- History," it'll take you to a new page:

The Catalog gives us a link to all the books in the system with a subject heading of "Chicago White Sox (Baseball team) -- History." It also includes a list of links to nearby subject headings, such as "Chicago White Sox Baseball Team Trials Litigation Etc."

In this case, if you'd looked up the book "Eight Men Out" and then decided you wanted to find out more on the history of the Chicago White Sox, you would simply click on the "Chicago White Sox (Baseball team) -- History" link in this list, and be taken to a new page which will list all the other items in the system which have this same subject heading:

Then it simply becomes a matter of looking through these other items dealing with the history of the Chicago White Sox in order to decide what else you might like to check out.

The primary purpose of the Subject headings is to help people find multiple resources on the same topic, as you see here. So how does the "Keyword" option fit in?

Let's try searching for something else. Summer vacation time is fast approaching, so let's say you want to plan a getaway to the Caribbean this year. (Hey, a librarian can dream, right?) First, let's try a Subject search with the heading "Caribbean guidebooks."

This is what we get:

As you can see, only two items in the whole system have the specific Subject heading of "Caribbean guidebooks." Does that mean that we only have two items in the whole system that could help us plan our trip to the Caribbean?

Maybe not. Let's try a Keyword search for "Caribbean guidebooks" this time:

And what do we get?

85 items come back this time. Why so many more?

Because when you search by Subject heading, the search will only look at the subject headings listed in each item's record. But when you search by Keyword, the search widens to include not only the subject field, but also the title, author, summary, publisher information, and pretty much every other word listed anywhere in the record.

For instance, when we look at the book "Caribbean Ports of Call:"

Note that none of the subject headings consist of the exact phrase "Caribbean guidebooks" (and when you do a subject search, you'll only get the results that consist of the exact phrase that were listed by whomever put the item into the Catalog). But the words "Caribbean" and "guidebooks" do show up somewhere in the record:

"Keyword" searches search everywhere -- title heading, author field, and words in the summary and description, as well as the subject field itself. So the "Caribbean Ports of Call" guidebook comes up when we try a keyword search, even though it didn't come up during a subject search using the same search terms ("Caribbean guidebooks").

Keyword searches are handy when you're searching for items on a particular topic and want to widen the search terms to include as many items as possible. You'll find Subject searches to be at their most useful when you've found a book that looks good and you want to see what similar materials might be in the Catalog. To go back to our "Caribbean guidebooks" example -- after finding the book "Caribbean Ports of Call" and deciding it was just the sort of thing you are looking for, you might click on the "Caribbean Area -- Guidebooks" Subject heading in order to see what other, similar materials you can find:

58 results -- not bad!

If you've gotten the hang of it, you might try hopping onto the Catalog and seeing what you can find. (And don't think you can only search for books -- CDs and DVDs have their own Subject headings, too!)

And if you have any questions, be sure to ask in the comments section. We'd love to hear from our readers!