There are three Boolean operators that are used to connect terms and tell databases how and what to search for: AND, OR, NOT.
AND is to combine terms, usually unlike terms/concepts. AND narrows a search. Example: social media AND teenagers
OR is typically used with synonyms and similar terms. OR broadens a search. Example: teenagers OR adolescents
NOT is used to exclude something. Example: teenagers NOT bullying
We use parentheses to help group parts of the search query, especially when we have several parts, and to tell the database the order of the query. Think about the search query as a mathematical equation.
All put together, they look like this: social media AND (teenager OR adolescent) NOT bullying
Truncation allows you to find different endings to a word. The symbol in many databases is: *
Example: teenage* captures teenager, teenagers, teenaged.
Be careful not to truncate too far into the word. For example: car* will capture car, cardiology, carbohydrate, caramel, carabidae, carassius, and thousands more words.
carbohydrat* would be a better way to truncate.
Wildcards are symbols used within a word to represent a letter for a variation on spelling. While not every database uses them anymore, for those that do, the symbol is often ? or $, though always best to check the database documentation.
Example: behavio$r captures both the American spelling, behavior, and the British spelling, behaviour