By default, NSF Funding, News, Discoveries, and site searches return results that contain all of the search terms entered.
In order to narrow or broaden results, it is often helpful to use search operators to refine the search query.
Supported search operators can be broken down into 4 main categories:
- Boolean Operators
- Required and Prohibit Operators
- Wildcard Operators
- Grouping Operators
Boolean operators (AND, OR, NOT) are used to narrow or broaden the search.
Note: Boolean operators must be in specified in upper case. Lower case and, or, and not are treated as search terms.
|AND||The AND operator is the default boolean operator. This means the AND operator is used by the search engine whenever there is no other boolean operator between two terms. The AND operator is used to narrow the search.
Records returned by the search must contain both the term on the left side of the AND,
as well as the term the right side of the AND.
Example: electronics AND displays
When the OR operator is used, records returned by the search must contain either the term on the left side of the OR,
or the term the right side of the OR, or both.
Example: river OR stream
|NOT||The NOT operator is used to exclude records that contain the term after the NOT.
Example: elephant NOT seal
Required and prohibit operators (+, -) are very similar to the boolean operators.
|+||The "+" or required operator indicates that the term after the "+" is required and must appear on any record returned by the search.
Example: electron +telescope
|-||The "-" or prohibit operator is equivalent to NOT and indicates that the term after the "-" is prohibited from appearing on any record returned by the search.
Example: elephant -seal
Wildcards (*, ?) serve as placeholders for one or more characters in the search term.
|*||The "*" operator matches one or more characters.
|?||The "?" operator matches a single character.
Grouping operators ("", ()) are used to create phrases and control order of evaluation.
|""||The quote operator,"", is used to group words into a phrase. Records are returned that contain the exact phrase.
Example: "wildlife refuge"
|()||The () operator is used to group search terms into subqueries.
Example: (river OR stream) AND pollution