When searching databases with keywords, you can use Boolean operators to combine those terms into a search string. The Boolean operators are AND, OR, and NOT.
The image below shows you how to use each of the Boolean terms within your search.
Searching with AND
When you connect keywords with AND you will narrow your search because you will only receive results that include BOTH keywords.
Searching with OR
When you use OR to connect keywords you broaden your search because the database will give you results that include either of your keywords.
Searching with NOT
When you use NOT with your keywords you narrow your search again because your results will exclude any sources including the second keyword.
Databases follow commands you type in and return results based on those commands. Be aware of the logical order in which words are connected when using Boolean operators:
​Truncation
Truncation is a technique that broadens your search to include various word endings and spellings.
Wildcards
Similar to truncation, wildcards substitute a symbol for one letter of a word.
Phrases
Different databases interpret searches differently. A common variation is how databases recognize phrases. Some assume that words typed next to each other should be searched as phrases while others automatically put a Boolean AND between your search terms, requiring that all the words be present, but not necessarily adjacent to each other.
Most databases allow you to specify that adjacent words be searched as phrases.
Search History
In many databases you can view your search history. This is important because it can keep you from duplicating an unsuccessful search, allow you to combine searches, and track your successful search attempts.
You can also set up alerts so the database will alert you to new articles/resources that match one of your searches.