Module 1 - Searching Expertise - Connectors

Connectors

Connectors (Boolean operators) are used in keyword searches to link together two or more terms. The most commonly-used connectors are AND and OR, though NOT is also useful. Older search engines required that connectors be capitalized, and it is good practice to do so.

AND narrows a search; you get fewer records, because all concepts must be present in every record found – the colored area below. Use AND to combine different concepts in one search.

computer AND history AND mathematics

OR broadens a search; you get more records because OR includes each of the concepts separately, as well as all concepts when found together. OR is often used to link together related concepts.

computer OR history OR mathematics

NOT refines a search by allowing you to exclude a term.

computer AND history NOT mathematics