Boolean Operators
Boolean operators are words (or, and, not) used to connect search terms to expand (or) or narrow (and, not) a search within a database to locate relevant information. Boolean operators are also called logical operators or connectors.
It is helpful to diagram the effects of these operators:
|
women or females |
Or retrieves records that contain any of the search terms. It expands the search. Therefore, use "or" in between terms that have the same meaning (synonyms) or equal value to the search. |
|
women and media |
And retrieves records that contain all of the search terms. It narrows or limits the search. Therefore, use "and" in between terms that are required to make the search specific. |
|
image not weight |
Not eliminates records that contain a search term. It narrows or limits the search. Therefore, use "not" in front of a term to ensure that the search will not include that term. Warning: Some databases use "and not" instead of "not." Check the database help screen. |
Keyword Searching Examples
Variety of terms: If you are looking for items on the "movies", use additional keywords such as "film", "films", "cinema", or "motion pictures".
An example of retrieving results unrelated to your topic (false drops): using the keyword "cricket" will retrieve items about the sport as well as the insect.
An example of using keywords to find titles when you are unsure of the exact title:
Both CAGED and BIRD are in 6 titles.
There are 6 entries with CAGED & BIRD.
You searched for the WORDS: bird caged
Found 6 items:
- Caged bird medicine : selected topics / Charles V. Steiner (1981)
- I know why the caged bird sings (1969)
- Many voices. 8A-6B (sound recording) : for Adventures for re (1986)
- Maya Angelou / Miles Shapiro (1994)
- Poco / by Garry and Vesta Smith; illustrated by Fred Crump (1975)
- Voices in Black & White : writings on race in America from H (1993)
Ask a Librarian
At reference desk most hours the library is open.
(818) 677-2285
http://library.csun.edu/AskUs
Limiting Search Results in the Library Catalog
You may further refine your search results by selecting 
when it is available.
Basic keyword searches and Advanced searches can be limited prior to submitting the search, or after by selecting 
. Search limits include publication date, language, material type, publisher, and location. Sorting results by year is also an option.
Keyword Searching
- Use keyword when your term may be very new, very distinctive, or jargon, e.g. "instant messaging", "XML".
- Use a variety of keywords. There may be additional items on your topic that use different terms.
- Be aware that you may retrieve items not related to your topic (called false drops)
- When you cannot remember the exact title of an item, do a keyword search using the title words you remember.
Truncation
- Most databases allow for a symbol to be used at the end of a word to retrieve variant endings of that word. This is known as truncation.
- Using truncation will broaden your search. For example,
bank* will retrieve: bank or banks or banking or banker or bankruptcy, etc.
- Databases and Internet search engines use different symbols to truncate. In general, most of the Library's databases use the asterisk (*) ; however, the exclamation point (!) is used in LexisNexis. Check the database help screen to find the correct truncation symbol.
- Be careful using truncation. Truncating after too few letters will retrieve terms that are not relevant. For example:
cat* will also retrieve cataclysm, catacomb, catalepsy, catalog, etc.
It's best to use the boolean operator "or" in these instances (cat or cats).
Wild Cards
Some databases allow for wild cards to be embedded within a word to replace a single character. For instance, in InfoTrac, you can also use the question mark (?) within a word to replace a character. For example:
wom?n will retrieve woman or women
Access Databases from Off Campus
Only current CSUN students, faculty and staff can access our databases from off campus. To access the databases from off campus, click the name of the database. You will then see a screen asking you to log in, using your CSUN User ID and password (the same ID and password you use to log in to the portal).
For more information, see Accessing Library Resources from Off-Campus and the Library's Copyright Statement (in particular, the Appropriate Use of Oviatt Library's Electronic Resources section).