To make the best use of library databases, it is important that you know their features and how each database works. You can find this information in each databases. Look for links labelled:
Make sure you know the order in which boolean operators are processed, what characters are used for truncation, whether controlled vocabulary (subject headings, descriptors) is available and other important factors that may affect your search results.
Once you have selected the keywords and/or phrases for your topic, familarize yourself with boolean operators. They are key to effective search strategies and allow you to combine multiple search terms in a single search statement. They can also be used to combine search statements. Databases like Omni, PsycInfo, PubMed and even Google use boolean operators.
Want to narrow your search? Include additional terms with AND or exclude terms with NOT.
AND - all terms will be included in the search results - knee and therapy. The And is implied in many, but not all databases.
NOT - excludes terms from the search results - knee not therapy
Need to broaden your search? Include alternate terms using OR.
OR - at least one of the terms will be present in the search results - replacement OR reconstruction
Whenever you have more than one Boolean operator (AND, OR or NOT) in a search statement, it is necessary to use parentheses in your statement. This is known as "nested searching." Operations enclosed in parentheses are performed first followed by the operators outside the parentheses.
Example: knee AND (replacement OR reconstruction)