Boolean Operators

Boolean Operators

The results of performing Boolean searches are sometimes illustrated by the diagrams below (called Venn diagrams.) The diagrams show graphically how using the AND operator narrows a search, using the OR operator broadens a search, and using the NOT operator excludes material from a search.

 

Operator	Example	The search will find...	Venn diagram results
AND	north carolina AND prohibition	items containing both "North Carolina" and "prohibition."
OR	zimbabwe OR rhodesia	items containing either "Zimbabwe" or "Rhodesia" or both. OR broadens a search, resulting in more hits.
NOT*	mexico NOT new mexico	items containing "Mexico" but not "New Mexico." NOT narrows a search. Caution! It's easy to exclude relevant items.

Boolean Bash

Now that you have read all about Boolean operators and what they can do to speed up and make your searches more fruitful, let's do some comparison shopping for the search engines out there and how they handle simple searches.

Using the word " tilinca ", we will run several engines through their paces!

(The site will open in a new window. Close it when you're done with the exercise.)

Ready, set, GO to Search Engine Showdown        http://searchengineshowdown.com/strat/advancedsearch.shtml


Choose Lesson 2--Exercises when you get to the Web site. Don't forget to come back to answer these questions!

1. Which search engine yielded the most results?

2. Did any of the search engines not have a clue?

3. What do you suppose makes it seem that way?

4. Which search engine did not have a very complete Boolean search engine?