After completing this tutorial, the student will be able to

Understand the difference between a keyword (free text) and a subject (controlled vocabulary) search
Explain which type of search strategy is better to use depending on the topic and database being used
Identify the subject headings or descriptors in a book or journal article citation
Demonstrate the ability to select appropriate keywords in conducting a keyword search
Determine whether a database has a thesaurus or subject guide available

Keyword searching:
A keyword search employs the use of any term you can think of that describes what you are researching. Most of us start with a keyword search when we are using the library’s online catalog, a database, or a search engine like Google or Yahoo. Almost any word in a citation, a Web page, or a full-text article can be used to find information on a topic. This is widely known as keyword, free text, or natural language searching and is a powerful tool.

Subject searching:
Subject searching provides access by using specific terms (“controlled vocabulary”) identified by a librarian, abstractor, or indexer familiar with the discipline or research topic. By using these subject terms you can be confident that most materials retrieved will be relevant to your search. Subject searching is more difficult for those of us who do not know the subject field well enough to understand distinctions among words used by that discipline. For example, if you are looking for books on colleges, it is difficult to know whether to use the subject heading of “college” or “university” or “higher education.”

Thesaurus
A thesaurus is a list of subject headings or descriptors created by indexers and librarians. These lists standardize headings by specifically defining which terms are used under what circumstances. A thesaurus also provides a cross-reference system to aid the researcher. For example, it helps identify a broader term (in case the term initially selected is too limiting), a narrower term (in case the term selected initially is too broad), and related terms (also known as “See also” terms). If you are using a term that is not used as a subject heading, a thesaurus will also guide you to the correct one by providing “See” suggestions. One example of a thesaurus is the Library of Congress Subject Headings guide used by librarians to select subject headings for books. These subject headings appear in a citation in the online book catalog. Another example of a thesaurus is the Thesaurus of Psychological Terms used by the American Psychological Association used to describe the subjects of journal literature in Psychology.

Boolean searching:
Boolean searching is a strategy used to combine terms in appropriate ways to ensure that results retrieved match what the researcher is seeking. There are three key Boolean operators: and, or, not. Here are examples of how these might be used.

“and” - By using “and” between keywords, you can retrieve articles that contain all of the terms; e.g., Miami “and” hurricanes “and” football – should retrieve articles that contain all three terms; so the articles should primarily be about the University of Miami football team.
“or” - By using “or” between keywords, you can retrieve articles that contain information on each of the terms; e.g., Miami “or” hurricanes “or” football – will retrieve articles on each of the three topics, resulting in possibly thousands and thousands of articles. “Or” is best used when you may have variant spellings of a name or a topic (for example, looking for the behavior of foxes around fox hounds might require “behavior or behaviour” to capture British articles), or when two or more words mean approximately the same thing (e.g., “youth” or “adolescents” or “teens”)
“not” – By using “not” between keywords, you can specifically eliminate certain aspects of a topic; e.g., Miami “and” hurricanes “not” football - should retrieve articles about hurricanes in Miami, but no articles related to the football team.

Keyword searching:
It is better to use keyword rather than subject searching as a starting point. Keyword searching is the easiest search strategy to use. When conducting a keyword search, you are encouraged to use the most distinctive words you can think of rather than common words or words which would often appear in the database you are using. For example, if you are doing a search in an education database, avoid using words like “school, student, education, elementary,” etc. Also, there is no need to include simple words like “of” or “with” unless they are part of a title for which you’re searching; e.g. if you are searching for a specific article entitled, “Running with the Bulls,” include all the words to limit your search results to that article.

The greatest problem with keyword searching is that it often retrieves too many items, many of which may be irrelevant to your topic. For example, searching for the keywords “Miami” and “hurricanes” could retrieve articles on Hurricane Andrew and on the University of Miami’s football team. To reduce the possibility of irrelevant results, databases often provide limiting options which allow you to search for keywords in specific fields; e.g., the keyword in titles only or in subject fields only. Another way to limit searches and improve the relevance of keyword search results is through the use of Boolean search techniques (see above).

Here is an example of a keyword search conducted first with “or” as the Boolean operator (note the number of results) and then with “and” as the Boolean operator (note the number of results).

Example 1

Example 2

Subject searching:
Subject searching provides more relevant results; however, it is also more difficult to use because you have to identify what specific subject term to use. Subject headings are not always intuitive. For example, if you search for World War I as a subject, you may find little since the actual subject heading is World War, 1914-1918 or if you search on Civil War as a subject, you will discover that lots of countries have had a civil war. It takes lots of scrolling to finally locate the heading you probably want – United States - History – Civil War, 1861-1865.

So, how can you quickly locate the subject heading you should be using? You can use a subject guide or thesaurus if that is available. Increasingly, these guides are becoming available in online databases. A tab or sidebar often indicates the availability of a subject guide or a thesaurus. See the following examples:

Example 3

Example 4

Since a subject guide is not always handy, however, another effective means of identifying a possible subject heading is by starting with a keyword search. For example, if you are looking for a cookbook on Southern cooking, you may type that phrase – “southern cooking” – in the keyword box of the “Basic Search” page of the library’s online catalog. The results return some rather strange titles [see below].

Example 5

If you look at the full citation for one which sounds like what you really want, however, you will see that the subject heading is actually, “Cookery, American–-Southern Style.” By clicking on that heading, you will find several more relevant titles. This search strategy could be called “Keyword to Subject.”

Example 6

Example 7

Subject Searching: Journal
Let’s do one more “keyword to subject” search, this time in a journal database. We will use InfoTrac OneFile as our database and search for what makes young people enjoy “hip hop music.” We type that term into the Basic Search box, and the results return 1,446 items. Item # 10, “Hip-hop. (MUSIC: new album for hip-hop artist Guru)” looks promising. I click on the title which returns the article including a link to “Subjects.” That link gives me several subject choices including “Rap (Music)” or “Hip-Hop Culture.” Since I’m interested in articles on the culture, I’ll choose “Hip-Hop (Culture)” and narrow the number of relevant items to 246, saving me a lot of time.

Example 8

Example 9

When using subject searching and moving from one database to another, be aware that subject headings used by one discipline or field of study may not be the same across other disciplines. For example, subject terms used by Psychology professionals may not be the same as those used by Sociology professionals or by Business professionals even though the topic itself is the same. It is advisable to use the thesaurus related to the database being used. Here is an example. We will look for the subject heading to be used when researching the topic of whether heredity or environment is a greater influence on human development. We will look at the subject guides available in each of three databases: General Science database, Biological and Agricultural database, and PsycInfo database.

Example 10

Example 11

Example 12

As you can see, both General Science and PsycInfo used “Genetics and Environment” as subject headings while Biological & Agricultural used “Nature and Nurture.”

One limitation to subject searching you should be aware of is that a subject search is restricted to a specific field in a citation – the subject field. A subject search will not search the title or author fields nor will it search the table of contents, notes, or abstract fields. Therefore, if you are doing a subject search and getting very few results, you might switch to a keyword search to obtain more hits and perhaps give you additional options for subject headings.

Subject searching is best used when the subject is either relatively simple, e.g., books on horses or articles on lung cancer, or when you have already identified the specific term used by that database to describe materials on your topic.

Keyword vs Subject Searching
Now for the critical questions:

When is it better to use a subject search?
When is it better to use a keyword search?
What are the advantages or disadvantages of each?

This chart provides some guidance on answering those questions:

Keyword Search	Subject Search	Which has the Advantage?
Free-text searching; no need to know specific, perhaps esoteric, terms that might be used	Controlled vocabulary; requires use of a guide to identify the most appropriate terms	Keyword Search
Lacks a guide to identify possible terms to use should the search be producing irrelevant results	Guide provides suggestions for other terms to broaden or narrow the search or to explore related areas	Subject Search
Searches terms regardless of location in the record; also may search all words in full-text documents	Searches terms only in the subject (also called the descriptor) fields of a record	Keyword Search
Usually retrieves a very large number of citations	Usually retrieves a smaller set of citations	Subject Search
Retrieves many irrelevant items	Most items retrieved will have a high degree of relevance	Subject Search

In all online journal indexing databases there are aids to assist you with developing an effective search strategy in that specific database. On the Databases A-Z list in the UWF library catalog (http://fusionmx.lib.uwf.edu/databases/), there is a column headed “Help.” In that column, you may either click on “G” for a Guide or “T” for a tutorial on how to use a specific database.

If you are already working in a particular database, however, and want to clarify how to do something, perhaps how to use proximity limits, you will find a “help” button. It may actually be titled “Help,” or it may be identified by a question mark (“?”).

Here are some related resources that you can use if you'd like to learn more about this particular topic.

“Keyword vs Subject Searching:” The Information Navigator. MIT Libraries, Cambridge, MA http://libraries.mit.edu/tutorials/general/subjectsearching.html
“Keyword and Subject Searching: A Comparison,” from “Guide to Library Research” tutorial. Duke University, North Carolina http://www.lib.duke.edu/libguide/key_searching.htm
“Library Skills Tutorials” Thomas J. Bata Library, Trent University, Peterborough, Ontario, Canada http://www.trentu.ca/library/help/skills/keyword.shtml
Search Help screens, Thompson –Gale, InfoTrac OneFile http://find.galegroup.com/itx/start.do?prodId=ITOF&userGroupName=pens49866 (The help screens for InfoTrac are very helpful in clarifying the Subject and Keyword searching and providing information on the use of Boolean and proximity strategies.)

Now it’s time to test what you’ve learned. Click here to test your knowledge. Be sure to print out your score or e-mail it to yourself or your instructor as proof that you have completed this tutorial.

Helen Wigersma

hwigersma@uwf.edu

September 23, 2005