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Boolean searching, available in most search engines, allows you to retrieve more specific results related to your research topic. The three Boolean operators are AND, OR, and NOT.
AND
The AND operator ensures that all search results must contain all keywords joined by the AND operator. The search below will return results that contain the terms beach and erosion.
Search: beach AND erosion
OR
When terms are grouped by the OR operator, all search results must contain at least one of those terms. The search below will return results that contain either or both the terms replenishment or restoration.
Search: replenishment OR restoration
NOT
NOT is the only operator where order matters. Any keyword after the NOT will be excluded from all search results. The searches below will return results that contain the term damage but not the term legal.
Search: damage NOT legal
( )
Parentheses, used in conjunction with Boolean Operators, are used to group concepts together in order to formulate more complex search statements or queries. This is called nesting. The search below finds results that contain the word beach and either the word erosion or the word damage.
Search: beach AND (erosion OR damage)
Are you searching with a keyword or phrase and having trouble finding relevant results? One trick you can use is to connect your keywords with Boolean Operators! Boolean Operators (AND, OR, NOT) are connectors that help us combine our keywords in specific ways for more relevant results. Check out this video on how Boolean Operators work in research.
A controlled vocabulary is an established list of standardized terminology for use in indexing and retrieval of information. A single term or phrase is assigned to represent a concept. For example, the term DWELLINGS may be used to represent the concept of DOMICILES, HOMES, HOUSES, and RESIDENCES.
Example: cat* retrieves cat, cats, cattle, catalog, Catanese, catnap, catnip, catastrophe, etc.
Example: wom*n retrieves woman or women