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Digital Search Tips

What to look for

To find subject headings for your topic:

  • Look to see if the database has an online thesaurus to browse for subjects that match your topic (check the Help screens).
  • The library has many print thesauri in the reference collection. 

Another way to find subject headings:

  • Start with a keyword search, using words/phrases that describe your topic.
  • Browse the results; choose 2 or 3 that are relevant.
  • Look at the Subject or Descriptor field and note the terms used (write them down).
  • Redo your search using those terms.
  • Your results will be more precise than your initial keyword search.

What are subject headings and keywords?

Subject headings describe the content of each item in a database. Use these headings to find relevant items on the same topic.  Searching by subject headings (a.k.a. descriptors) is the most precise way to search article databases.

It is not easy to guess which subject headings are used in a given database. For example, the phone book's Yellow Pages use subject headings. If you look for "Movie Theatres" you will find nothing, as they are listed under the subject heading "Theatres - Movies."

Keyword searching is how you typically search web search engines.  Think of important words or phrases and type them in to get results.

Here are some key points about each type of search:

Keywords
 vs.
Subjects
  • natural language words describing your topic - good to start with
  • pre-defined "controlled vocabulary" words used to describe the content of each item (book, journal article) in a database
  • more flexible to search by - can combine together in many ways
  • less flexible to search by - need to know the exact controlled vocabulary term
  • database looks for keywords anywhere in the record - not necessarily connected together
  • database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear
  • may yield too many or too few results
  • if too many results - also uses subheadings to focus on one aspect of the broader subject
  • may yield many irrelevant results
  • results usually very relevant to the topic

When you search a database and do not get the results you expect, please ask a librarian for help.

Attribution

These pages are based on a guide developed by the Massachusetts Institute of Technology (MIT) Libraries.  They are used here under the creative commons (cc) licence.  The original pages can be found here http://libguides.mit.edu/c.php?g=175963&p=1160724