Web search engines like Google assume you want to search all terms you type in. Other web search engines rank by relevance - results with all terms come up first, then results with only one term. Library databases have more sophisticated search capabilities and requirements; you must specify how the system should deal with multiple terms.
Use the operators AND, OR or NOT to combine keywords or phrases.
- AND narrows a search - results must contain both terms.
Use AND to combine separate concepts.
- OR broadens a search - results can contain either term, or both.
Use OR to combine synonyms.
- NOT narrows a search - results can contain one term, not the other.
Use NOT to exclude terms
|Operator||Sample Search||The search will find...||Diagram of Results|
|Items that contain both
"careers" and "medicine"
|Items that contain either
"occupations" or "careers"
|Items that contain
"assisted suicide" but not "kevorkian"
A symbol at the end of a word stem provides for all variants on the word stem. The most commonly used symbol is the asterisk (*), but this varies among databases.
For example, a search for
library, libraries, librarian, etc.
Be careful not to truncate too far, or you will retrieve unrelated words!
A symbol within a word provides for all possible variants inside a word or word stem. The most commonly used symbol for internal truncation is #. For example, a search for
Look at online help for each database to determine the truncation symbols.
Some databases require a phrase to be in quotes. Ex: "higher education"
Content based on Duke University Guide to Library Research: Electronic Searching