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Library Tutorials

Tutorials for Online Library Resources

Boolean Modifiers / Operators

Boolean modifiers, operators, or connectors broaden or narrow your search. They used in the Advanced Search option in the GIL-Find catalog, GALILEO, and other databases.

  • AND – narrows your search. All search terms following the AND must be in the record.
  • OR – broadens your search. Either search term must appear in the record.
  • NOT – narrows your search by excluding or ignoring words. The first search term must be present, but the search term following NOT will not appear in the record.

Parentheses can be used to group Boolean operators.

Phrase Searching

Quotation marks keep words together as phrases for most databases. However, not all databases or search engines recognize this method. Some databases or search engines use parentheses or single quotes instead. 

Credit: North Carolina State University Libraries on YouTube

Truncation and Wildcards


Truncation uses the asterisk (*) to help you broaden your search to include words with various endings or spellings.

     Example: Use educat* to include search results with educate, educated, education, educational, educator.

Wildcards also use symbols to help you find variations of words.

    Example: Use wom?n to get woman or women, or use col?r to get color or colour.

Truncation and wildcard symbols vary by database or search engine, but common ones include the symbols *!?, or #. Check the database’s Help page before you search.

Source: Online Research: Tips for Effective Search Strategies by Sarah Clark on YouTube