boolean searchingA method of combining concepts in a search which allows the searcher to narrow or broaden the focus of a search; boolean logic uses 3 logical commands or "operators": AND, OR and NOT.
Boolean search commands
Used to expand or broaden search results to include synonyms and related terms.
“Violence or conflict or aggression”; this search string would retrieve any record that held any of those 3 words.
Used to narrow or restrict search results.
“Violence and conflict and aggression”; the search string would retrieve any record that contained all of those 3 words; however, the search would not retrieve any record that had only 2 of the 3 terms.
Used to further restrict search results.
“Television and broadcasting not video”; here the search string would retrieve records that had both the terms "television" and "broadcasting" but would eliminate those records if they also contained the word "video".
The addition of parentheses enables the searcher to specify which segment of the search string is to be evaluated first.
“Television and (violence or aggression)”; here, the search engine will look first for items that contain either of the terms "violence" or "aggression"; it will then narrow down those search results even further to contain only the records that have the word television as well as either of the other 2 terms.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.