The Research Process

Boolean logic combines search terms using three basic commands, known as Boolean operators. There are three basic Boolean search commands: AND, OR and NOT.

• OR searches find one term or the other.  Searching for COVID-19 OR pandemics OR influenza will yield materials that contain any of those search terms. The OR operator is most helpful when looking for synonyms. It is a method to expand or broaden your search.
• AND searches find all of the search terms.  Searching on "community risk reduction" AND "public education" returns only results that contain both search terms. AND limits your search results. Using AND is a way to home in on your topic.
• NOT eliminates items that contain the specified term.  Searching for COVID-19 NOT "1918 flu epidemic" returns items that are about COVID-19, but will specifically NOT return items that also discuss the 1918 flu epidemic.  This is a way to fine-tune results.

Use Boolean logic to search the library catalog and our subscription databases.

Boolean logic also works when searching the web. Google's advanced search page talks you through the process (see above). But you can also type your Boolean search into the main search using the following conventions:

• Capitalize OR
• Use the minus sign (-) for NOT
• Don't bother with AND since that is Google's default  for groups of words
• Use "quotation marks" for exact phrases

You can use Google to search social media. You can also use it to search for information about a website or to search a specific website or domain using the following:

• SITE: The search string "site:.fema.gov community risk reduction" will search that site for community risk reduction.
• RELATED: The search string "related:nfpa.org" will find similar sites.
• CACHE: If you're having trouble getting on to a website, try using the search string "cache:usfa.fema.gov" to see Google's most recent copy of the site