boolean logic using boolean logic to more effectively search the internet and databases karen yurish...

Boolean LogicUsing Boolean Logic

to more effectively search

the internet and databases

Karen Yurish

May 2004

What is Boolean Logic?

• George Boole, 19th century mathematician (Bopp and Smith 100)

• Form of symbolic logic which “uses common words . . . to create and manipulate sets” of information (Bopp and Smith 101)

Benefits of Boolean Logic

• Broaden Search

• Narrow Search

O R

T ru n c a tio n

L o g ic to B ro a d e n yo u r S e a rch

OR

• Will yield results that have either one search word OR the other

• hornets or wasps will give you results that contain either word

Truncation (*,!)• Shortens a word or eliminates characters to

search for many forms of a word

• Also called “wildcards” or “stemming”

• presiden* will search for president, presidents, presidential

• wom*n will search for woman and women

A N D

N O T

Q u o ta tio n M a rk s

P ro x im ity

L o g ic to N a rro w Y o u r S e a rch

AND (+)

• Will search for results which ONLY contain both of your search words

• harmony and hornets will only find results that contain BOTH words

NOT (-)• Will eliminate terms from your search

• rock not music will only search for physical rocks, not musical bands

Quotation Marks

• Quotation marks will search for the EXACT PHRASE in quotation marks

• In this way, you limit the search to an exact phrase

• “Harmony Intermediate School” will yield results with that exact phrase

Proximity• Proximity is a refinement of the Boolean

operator AND (Bopp and Smith 107)• A special operator is used for this search

such as adj (adjacent) or n (near)• harmony n/3 drama would give you a result

such as “Harmony Intermediate School Drama Club . . .” because drama is at most three words from harmony

Advanced Searches

• Still not finding what you need?

• Use the “Help” Section in any search engine or database to do an even more advanced search

Works Cited

Bopp, Richard E and Linda C. Smith. Reference and Information Services: An

Introduction, 3rd edition. Englewood, Colorado: Libraries Unlimited, 2001.