Combining Search Terms
When you do an electronic search you usually need to use more than one keyword. Multiple search terms can be combined together using logical or Boolean operators. The most common Boolean operators are AND, OR and NOT.
AND
-
Combine search terms with AND to find results which contain ALL the words.
-
The AND operator narrows a search, making it more specific and reducing the number of hits.
-
Most Internet search engines use AND as their default if you don't tell them otherwise.
|
|
|
-
Combine search terms with OR to find results which contain ANY of the words.
-
The OR operator broadens the search, increasing the number of search results.
-
It is useful for finding synonyms or where different words are of equal value in your search.
mobile OR cellular
NOT
-
Combine searches with NOT to find results that contain the first term without the second.
-
The NOT operator narrows a search by excluding all results containing the specified term.
-
It should be used with care as it can easily exclude relevant results.
football NOT soccer
Complex search statements can be constructed using parentheses.
eg. (mobile OR cellular) AND (telephones OR phones) would find results which contained mobile phones or cellular telephones etc.
Some Databases also allow you to do separate searches and
then combine the sets of results:
| Search #1 | mobile OR cellular | results #1 |
| Search #2 | telephones OR phones | results #2 |
| Search #3 | #1 AND #2 | result as in example above |
Truncation
-
Truncation can be used to find words with the same stem, therefore including plurals and other variations of a word.
-
A search for Chemist* will find chemist, chemists, and chemistry.
-
Truncation symbols vary for different databases, the most common being * and ?
eg. (mobile OR cell*) AND (telephone* OR phone*)
Need further assistance?
Ask InfoHelp
If this information is inadequate, incorrect, or can be improved in any way, please let us know