Search tips: Wildcards, Truncation, and Boolean – What do they all mean?

You may be aware of the simple search strategy we librarians like to call Boolean. It's a form of database logic that connect your search words together to either narrow or broaden your set of results.The three basic Boolean operators are AND, OR, and NOT and you can use these to broaden or narrow your search.

Use AND in a search to:

• narrow your results
• tell the database that ALL search terms must be present in the resulting records
• for example, Dogs AND cats – results containing those two keyword
• For example, Google automatically puts an AND in between your search terms.

Use OR in a search to:

• connect two or more similar concepts (synonyms)
• broaden your results, telling the database that ANY of your search terms can be present in the resulting records
• for example, Dogs OR cats – broadens results

Use NOT in a search to:

• exclude words from your search
• narrow your search, telling the database to ignore concepts that may be implied by your search terms
• for example, (Dogs AND cats) NOT puppies – narrows results

Be aware:  In many, but not all, databases, the AND is implied. 

There are extra tools you can use to help refine your search strategy, these are called wildcards and truncation.

Truncation help by broadening your keyword search by attaching to the root of a word, this is usually done by adding an asterisk to the end of the root of a word.
For example:

Child* = children, children’s, child’s, childhood

Wildcards are useful when multiple spellings of a word can affect your search. Remember, the symbol of the wildcard may change depending on which database you use.
For example:

coloni?e = colonise, colonize

 Wom!n = woman, women

For more information visit Info Skills Road Trip - Search Strategy libguide.
Image source: http://s3.amazonaws.com/libapps/accounts/11249/images/Boolean.png