Controlled Vocabulary Searching

LIS 4/5523: Online Information Retrieval

Dr. Manika Lamba

What Search terms Should I Use?

There are no wrong answers here

1. Use the word “tear” in a short sentence

2. Were you thinking

Interesting. Okay, let’s go on to the next question.

3. Use ONE (and only one) word to describe this picture.

Ready, Good!

4. Were you thinking

Let’s do a quick exercise. There are no wrong answers here!

So, first try to use the word “tear” in a short sentence.

Were you thinking, about (i) tearing a piece of paper or (ii) tears coming down from eyes.

Okay, let’s go on to the next question: Use ONLY ONE word to describe the picture on the slide.

Were you thinking: globe, world, planet, space, or earth??

Language is Complicated

Do you see the pattern in the previous questions? What might seem like a simple word or an easy name can actually be quite complicated. This makes searching, especially in a library database, just a little more challenging. The good news is that if you learn a bit about the way a database works, you will be able to find useful information much more quickly.

Find It

Have you ever used the “find” option in a document? Let’s say you want to find the word “zombie” but a few times you decided to spell it “zomby” and once you misspelled it “zmbie”. Will it “find” either of these? No, because you told it to look for “zombie”.

But why cannot you find anything helpful?

A database is like a more complicated version of that “find” option. A database just uses the input you give in the search boxes to “find” items that match. Most databases can search for multiple terms at once or cross-reference to narrow or broaden the results. But it can only do that based on the information YOU give it.

Databases Cannot Think

If you are looking for an article on the world, but the database uses the word “earth” you may not get many results. Or you might even get zero results. This might make you think the database has nothing useful to offer. Or say you need to write a paper on the Greek god Mercury. You search for the word “mercury” but get results mostly about the element mercury and the planet mercury. There might be a lot of results, but they might not be useful ones. This is where controlled vocabulary can help!

Why Do We Need to Control the Vocabulary?

Controlled vocabulary is what sets a database apart from a general “find” search or a general web search. Every article, essay, or item in a database has been “tagged” with terms that let you know what it is about.

Think of a picture you post on your Instagram. You can tag a picture with anybody’s name and there would be no one who could stop you.

In fact, any of your friends could, depending on your privacy settigns, tag anyone they wanted in one of your pictures.

Tag, You’re It!

With the library databases, the tagging for subject terms is controlled. People such as librarians, authors, and publishers have taken time and effort to match articles and books to accurate “tags” or “SUBJECT TERMS”.

These terms are not perfect – after all, librarians are people too – but they are designed tp gather information in a more specific way.

Choices, Choices

There are different ways you can use subject terms. We will review two ways that you might find most helpful. The first is doing a broad search and selecting a subject term or terms from the results. The second is to use the database’s Thesaurus to find subject terms.

In next few slides, I will be using EBSCOhost Academic Search Complete for my examples. Every database has its own quirks and differences, but these broader principles can be applied to many if not most of them.

You Have to Start Somewhere

In AE#4, you had the experience understanding the different functionalities of the database assigned to you. You tried doing a search using the limits that are available. Try it again with some different database. Use more than one search term and limiting it to peer review only, for example, you can make your result list a little more manageable.

Do not be afraid to try something. The worst that could happen is that you have to try a new search.

Even though this search only brought up 4 results, there might be something useful here. Even if none of these articles are useful, their subject terms might help us find what we need. The subject terms are located under the description of the articles.

Hyperlinked!

If you click on results to get the full description, a lot of databases offer subject terms as hyperlinks. Clicking on a subject term will bring up all the other articles that are also tagged with that subject term.

Special Designators

By clicking on the hyperlink, the database will use a code to let the search know you are looking for a subject term. For Academic Search Complete this designator is DE. It will be different for different databases. Now that we know what it is, we can use it to combine multiple subject terms.

Mix and Match

If the subject term contains more than one word, using quotation marks will tell the database to look for phrase instead of 2 individual words. We can pull subject terms from different articles to get more precise results. See what happens when we use the subject term “ILLEGAL aliens” from our first result and “IMMIGRANTS” from our second results.

You may have to mix and match different subject terms to get the results you really want. Or to narrow the list down so it won’t take you 14 hours to sort through! And if your first search does not bring your articles that have useful subject terms you will have to try other general searches to try find some.

It's called REsearch because you have to search and search again!!

All this is good, but maybe you want to just start with the subject terms. Is there a way to do that? I am glad you asked!

Thesaurus

A lot of databases (though not all) offer a thesaurus or list of subject terms. These differ based on the database, but if there is one it can save you some time. Academic Search Complete simply says "Subject Terms" at the top. And clicking on it will bring up a new kind of search screen.

This search is designed to help you find specific subject terms, so be as simple and straightforward as possible. There are two options: "Terms begin with" and "Term contains"

Start with "Terms begin with" but if few to no results come up, try "Term contains" to broaden the results.

Term Begins With

See on the slide how "Terms begin with" differentiates between the different kinds of mercury? It will help you focus in on just the type that you need.

When you click on a term, it will give you more information:

• "Scope Note" will let you know what that subject term is used for

• "Broader Terms" are subject terms that will open your search up further

• "Related Terms" are other subject terms that are very similar or synonyms

• "Used For" shows terms that are not subject terms in the database. This lets you know that you should use the official subject term instead

Step by Step

[Click Next to view the pictures]

If you have found the subject terms you need, the thesaurus usually makes it pretty easy to add them to your search. Select the check box of the term(s) you want to use.

If you are selecting more than one term and you want to expand your search to results that contain either or both subject term, use the “OR” connector to expand your search.

If you are selecting more than one term and you want to limit your search to ONLY results that have BOTH terms use the “AND” connector.

For more on “OR” and “AND” connectors watch last week’s lecture on searching techniques and strategies.

Clicking the “Add” button will automatically put the search terms into the search box. You can then look for more subject terms or perform your search.

Compare and Contrast

So here’s a great example of why using subject terms can make your searching so much easier.

On the left, I just typed “mercury” as a keyword. The database gave me over 32,000 results — way too many! And as you can see, most of them are about mercury the chemical element — pollution, water studies, toxicology — nothing to do with the Greek god Mercury that I was actually looking for.

Now, on the right, I used subject terms instead. That means I told the database exactly what concept I wanted — in this case, Mercury or Hermes, the Greek or Roman god. And look at the difference: only 41 results, all much more focused on my topic.

Keywords just look for words anywhere in the record, but subject terms capture meaning. Using them helps you move from thousands of random hits to a manageable set of relevant ones.

Another Quick Note About Thesaurus

Here’s another quick note about using the thesaurus in databases.

If I search for the term “attorney,” I get a message saying that term isn’t found. But the database helps me out by offering suggestions — and notice what it shows: most of the recommended terms use “lawyer” instead of “attorney.”

That tells me that in this database, “lawyer” is the preferred term. So, if I want to find all the relevant results, I should use “lawyer” when building my search.

You can also click on any of these suggestions to explore related subjects or run a new search with “lawyer” to see even more options.

So, when your search term doesn’t show up, don’t panic! The thesaurus can guide you to the right subject term that the database actually uses.

Putting it Together

Subject Terms are like “tags” that have been attached to items in a database to make them easier to find. You can find them attached to an article or item and use those subject terms to find other similar items. Or you can use a thesaurus or subject term list to find subject terms to focus your search.

Now, you know a little bit more about the way Subject Terms work in a database. Playing around with them can help save you time when you are doing research for a project. The more familiar you are with the way a database works, the easier it will be to find items that are useful.