Welcome to this UW Libraries tutorial on using controlled vocabulary.
In this tutorial we will cover the differences between keywords and
controlled vocabulary
and the advantages and disadvantages of using controlled vocabulary
in database searches. Controlled vocabulary are standardized words and
phrases
that have been created for purposes of indexing and information retrieval
in the context of a catalog or database. Examples of familiar types
of controlled vocabulary
include subject headings and author names. A book index is another good place
to find controlled vocabulary
as are the way names are listed in a phonebook. Unlike keywords, which are
generated
individually and intuitively by database users and may or may not return results
in a search.
Controlled vocabulary are created by indexers specifically to describe items
within a database
and so are guaranteed to produce at least some results. For instance,
you might search a database for the keyword "cooking" and get 50 results
but get 80 results by searching on the subject heading "cookery."
There are many advantages to using controlled vocabulary as part of a
database search.
One of the biggest advantages is the fact that controlled vocabulary can help
you quickly and easily discover a core group of resources
that are highly relevant to a given concept. In this way,
controlled vocabulary searches are much more consistent than keyword searches
which can easily produce results with only a vague relation to the actual topic you
are researching.
Another advantage of controlled vocabulary is the fact that they can be
combined with either additional controlled vocabulary
or with user-generated keywords in order to produce even smaller subsets of search
results.
While controlled vocabulary are powerful tools
there are also some disadvantages to their use in certain search contexts.
For instance, controlled vocabulary are by definition
"controlled," which means that they may not be as flexible as keywords in capturing
new phrases,
topics, and ideas as they enter into the literature. It can also be difficult to
determine whether you have selected the best controlled vocabulary term for a
given search topic
as they are sometimes unintuitive, hard to differentiate,
or apply to resources in a way that does not fit your interpretation of their
scope.
For this reason, it is useful to experiment with both keywords and
controlled vocabulary
when searching a new database. It is also recommended that you browse records
or indexes to get an initial sense of how controlled vocabulary
relates to your research. We will now look at a brief example of the use of
controlled vocabulary
in a UW Libraries database. Let's begin by taking a look at one of UW
Libraries popular databases,
Communication & Mass Media Complete. Here we see a basic
EBSCO search interface but there are three fields for entering keywords.
Under normal circumstances we might begin by entering keywords,
such as "social media" into one of the fields and hitting "search."
By performing this search
we find 2,301 results related to the keyword social media.
One way to get started with controlled vocabulary is to go and look at a few
of these results records and find which controlled vocabulary terms
pop up in them. For instance let's go ahead and click the first result
"Playing In The Same Twitter Network." Within this article record we see
there's a number of links that appear
some of which represent controlled vocabulary. For instance,
we see a number of author names, a source title, and then subject terms,
each of which is controlled carefully by the database. Subject terms represent one
of the most popular types
controlled vocabulary, as we have discussed. So in this case,
it might be helpful to click on one of the subject terms in order to find
other articles
and results related to the same subject. Let's go ahead and click on "Online
Social Networks" to learn more.
As you can see we've performed a new search based on this controlled
vocabulary subject heading.
It's produced 1,271 results,
so a smaller field than our initial search for "social media."
Another way to discover controlled vocabulary
once you have started with keyword searches, is to look to the left or right side
filters within the database to see if they lend any clues.
For example, if we look to the left side of this database,
we'll see there are some suggestions for additional subject terms
which we could add to the search or substitute for the term "online social
networks."
The subjects designated thesaurus term are the ones best mapped by the
database.
Let's go ahead and add the term "social media" in order to see what happens.
As you can see, this has narrowed our results once again now down to 158.
Another way that we could access subject thesaurus terms is by going to the top of
the page
and browsing the databases actual thesaurus.
The thesaurus is a useful tool as it allows us not only to discover new
controlled vocabulary through browsing,
but to check the validity of terms that we think might make good subject headings.
For example, let's go ahead and pretend like we wanted to find subject headings
related to the idea of "social media."
By using the "begins with" browse option we could see here that there is in fact a
subject heading
for "social media" within the database.
By clicking it not only do we find the details of the scope of this term
but also ideas for broader and narrower terms, which may be more relevant to our
search.
For instance, we see there's a broader term for "communication" as well as a narrower
terms
like "computer bulletin boards" and "podcasts." Let's go ahead and select "podcasts" in order
to see what happens.
Now that we have added this controlled vocabulary term to the field above,
we can go ahead and perform a new search.
Here we have quickly and easily found 63 results related to the
narrower term "podcasts" within the database. If we wanted to discover
which of these results contained a specific phrase "social media"
we could add that to the secondary field to the left, and then hit "search" again,
combining keywords and controlled vocabulary.
This last search produces 7 results, a very tight circle of information for us to
continue to explore.
In this tutorial we covered the definition, pros, and cons of searching
with controlled vocabulary.
Thanks for watching! If you need further help please feel free to ask a librarian!