Whether you are searching the library catalog or one of the databases we subscribe to you can search with two different sets of vocabulary. Keywords are words related to your topic that you may use in every day speech or within the field you are studying. Subject Terms (sometimes called index terms) are the specific words and phrases the database uses to organize information.
Keywords can be a helpful way to search if you want to do a broad, expansive search into what information there is on a topic. It can be helpful to start your search by creating lists of keywords and synonyms you may use in your research.
Subject or Index terms search in a specific, field or database related way. Database thesauruses help you find the correct subjects to use and often organize the terms to list broader, narrower and related terms; a helpful way to revise your search strategy.
When you search using AND, databases look for articles that have both search terms. It is useful in narrowing down your search by combining ideas, like this:
When you search using OR databases search for articles that have either or both of the search terms you used. It is useful when you have two search terms for the same idea.
When you use NOT, the databases remove a term from your search. This is helpful if you find that searching one term has some useful information, but a lot of articles on a related topic you don't want. You can still look through most of the results, but remove extra articles.
You can use AND, OR and NOT together to create stronger searches in our databases:
((College students OR (undergraduate students)) AND sleep)
...To search for one part of the search in many ways.
((gills NOT fish) AND evolution)
...Or to remove a term from a wider search you are conducting.
Try this out yourself with your next search!