Executing a Search Strategy
Research Databases
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HOMER
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Journal Articles
Citations, Abstracts, Full Text
Boolean Logic
Basics of Searching:
AND, OR, NOT
Web Search Engines
What they are,
how they work
Questions or Comments?
Email:
kathy.labadorf@uconn.edu
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Basics of Searching: Boolean LogicBoolean Logic uses AND, OR and NOT to retrieve items from a database. Often, in Web search engines, these words are replaced by characters such as + and - , but many commercial databases such as PsycINFO and Medline use the actual words AND, OR, NOT.Boolean concepts are often explained with Venn diagrams - circles which represent sets of data containing the required information. 
This set includes information on dogs
This set includes information on cats
The Boolean operators AND and OR seem to mean the opposite of their natural language: OR is inclusive (either this or that), AND is reductive (both this and that): AND retrieves records that contain both words.
This set includes information on both cats AND dogs OR retrieves records that contain either word.
This set includes information about either cats OR dogs NOT removes any information containing the word. It can eliminate from the results some useful information, however, because it does not weigh the significance of the word in the records. If the article is primarily about dogs and only mentions cats incidentally, the record will not be retrieved. NOT should be used carefully. 
This set includes information about dogs but NOT cats
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