LibGuides: Database Search Tips: Keywords vs. Subjects

What are keywords and subject headings?

Keywords are words or phrases that can appear anywhere in the item (citation data or full text of a book or an article). Keyword searching is how you typically search web search engines and it is a good start to find relevant subject headings in databases.

Subject headings are formally assigned, standardized set of terms (also called descriptors) within a database to identify the primary topics of a book or an article.

It is not easy to guess which subject headings are used in a given database. For example, you have a keyword "wage gap" in mind but the closest subject headings for this concept is "wage differential" in the ProQuest Dissertations & Theses Global database.

Here are some key points about each type of search:

Keywords	Subject Headings
natural language words appearing in the item (citation data or full text article) - a good place to start finding subject headings	pre-defined "controlled vocabulary" used to describe the content of a book or a journal article in a database
more flexible to search and can combine together in many ways using Boolean operators	less flexible to search since you need to know the exact subject headings
database looks for keywords anywhere in the item	database looks for subjects only in the subject heading or descriptor field
may yield too many or too few results	you can also uses subheadings to focus on one aspect of the broader subject term
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, Contact us for advice.

How to find subject headings

Keyword searches

Start with a keyword search, using words/phrases that describe your topic.
Browse the results; choose 2 or 3 items that are relevant.
Look at the Subject or Descriptor field and note the subject terms used.
Redo your search using those terms.
Your results will be more precise than your initial keyword search.
Limitations of subject headings: for very new concepts e.g. "illiberal democracy" the databases may not have current subject terms.

Thesauri

Look to see if the database has an online thesaurus to browse for subjects that match your topic (check the Help screens).