Boolean operators are words used to connect two or more terms within a search. They are commonly "AND," "OR" and "NOT." Here are some tips for using each different connecting word.
AND will make your search smaller. If you are retrieving too many records on your topic, try adding another search term with the operator AND.
For example: "krispy kreme" AND marketing
OR will make your search bigger. If you are retrieving too few records on your topic, try adding another search term with the operator OR.
For example: (adolescents OR teenagers)
NOT will exclude a word from your search results. If you are retrieving too many records on an unrelated topic, try eliminating a word with the operator NOT.
For example: dolphins NOT football
Keywords
These are words and phrases you have thought of that describe a topic you would like to research. Keyword searches are typically how you begin your research; simply enter the words that come to mind regarding your topic. Usually a basic keyword search will retrieve many search results, because any items that mention your keyword(s) at least once anywhere in its text or record will be retrieved.
Combine keywords with the Boolean operator "AND" in between each keyword in order to research a topic with multiple concepts. For example, "college students AND study habits," "French literature AND existentialism," or "exercise AND knee injuries."
Subjects
These are very specific terms assigned to a source by a database or other authoritative group to describe an information source as a whole. When searching by subject, it is very important to use the exact spelling and/or word order of a subject term being used. Searching by subject is very precise; usually, not many search results will be retrieved, but the sources retrieved should be very relevant to your topic.
Advanced search options in library search tools usually provide subject searching. The challenge is to first find the exact subject terms/phrases to use. You may have to perform several basic keyword searches until you find a good source and notice the subject terms in the item's record. In this search result page using EBSCOhost, notice the "Subjects" listed for each source as you make your way down the page. It would be beneficial to "borrow" subject terms that describe your search topic and start a new search using those exact subjects.