A Boolean search is made up of terms connected by the operators AND,
OR and NOT. Computers cannot understand human language, but they can match
words. By using a combination of keywords and Boolean operators you can
refine and modify your search:
Boolean operator |
How it affects your search |
Exercise AND altitude |
- Narrows a search by requiring that each keyword separated by
AND must be included in the documents found
- When searching for exercise AND altitude,
both terms MUST appear in the documents
|
exercise OR mountaineering |
- OR requires that at least one of the keywords strung together
with OR will be in the documents found
- When searching for exercise OR mountaineering,
either of the two terms will appear in the documents, or both
of them.
- OR is effective for stringing two like terms (synonyms) together.
|
 Exercise NOT mountaineering |
- NOT or AND NOT excludes documents following this operator.
- When searching for exercise NOT mountaineering, documents
will be retrieved containing information about exercise, but exclude those with the word mountaineering.
|
| Nesting or Parentheses ( ) Groups terms together
and specifies in what order the search should be executed |
- Using parentheses to surround some words in your search requires
those words to be searched first
- Parentheses are required when you are grouping terms separated
by OR (exercise OR mountaineering) and there is another Boolean
operator in the search; see below example
- When searching for altitude AND (exercise OR mountaineering), you will retrieve information about altitude,
and either exercise or mountaineering.
|