When you're choosing words to search for, remember that there are many different ways to describe the same idea. For example:
dog: canine, puppy, Dachsund, mutt...
You can't find what you don't search for. If you search for the terms dog and health, you won't find sources that only use the term canine to talk about dogs. Remember to search for variations of your term.
In the example below, think of each circle as a word or concept you're using in a search.
While you can use OR to combine dissimilar things (cats or dogs), you'll more often use OR to combine similar concepts. This helps you pull in a more comprehensive set of records.
In the top example, we want to make sure that we get all articles related to testing, so we connect assessment and examination. Once we have a set on testing, we narrow with a different concept using AND. You can combine AND, OR, and NOT to build very complex searches. Group each concept in parentheses.
Let's say that we only want to look at topics for college testing, not K-12. We need to include college results and exclude earlier grades:
(test or assessment or examination) AND (college or university) NOT (elementary or "middle school" or "high school").