Searching for a subject heading instead of a word that happens to appear anywhere in a record can reduce the number of irrelevant records retrieved from your search.
WARNING! Each database will have a different way of letting you combine subject heading searches. You'll need to experiement a bit.
The Index is the list of words used by all the records in a database. A database does not directly search its records but actually searches its Index for your word(s), which then tells the database which records contain those words. Some databases allow you to browse the Index directly.
Example: The PubMed database contains four separate indexes: a Phrase Index, a Journal Title Index, an Author Names Index, and MeSH Headings.
Stopwords are words that are not included in the Index of the database. That is why those words cannot be searched.
Make a list or use the chart below to track keywords related to your topic.
Keep it by your side when you start your research.
Ever wonder why you couldn’t find any articles on a topic when searching by subject? Think of subject headings as tags assigned by each database vendor to the articles. Do remember, however, that each vendor chooses their own set of tags. So, what works in one database (Academic Search Complete), won't necessarily work in another (Proquest PsychInfo). This tagging of specific subject headings is called "controlled vocabulary."
|Keyword Searching||Subject Heading Searching|
|Good for obscure or contemporary topics||Good for general and universal topics|
|Can generate many irrelevant results||Lists highly relevant results for each topic|
|Can use any term to describe topic to find relevant information||Need to know specific subject heading or vocabulary to search in subject heading list|
|Will search for keyword in any field||Will only search in subject heading or descriptor field|
So, how do I figure out which is the right tag to search for????
Use the Subject Guide/Thesaurus/Index to verify the subject tags to search for. It takes your term or phrase and suggests EXACT words or phrases used by the database to find articles on that topic. You’ll want to look up several terms that match your ideas in order to find the best terms “tagged” on your topic .
For example, if I search for the subject <Cat's Cradle> in ASC Subject Guide, it tells me to use <String Figures> instead.
If I had just searched for Cat's Cradle, using the field limiter Subject, I wouldn't have had any results.
What if you want to search for articles about boys but there are multiple subjects and you're not yet sure of what exactly the search term might be. You can type in <Boys*> (see Truncation) and, depending on the database you're in, find all the subject headings with that word in it, including <Backstreet Boys (Musical Group)> and <Teenage Boys>.
Think of your search as a word cloud--trying out multiple terms gets you the broadest results for your search. Once you find them in the Thesaurus, you can click on them to add them to your search string. For narrower results, you can combine several subject terms to get very focused results.