November 2, 2010

From Boole...to Google?

Happy Birthday, George Boole

Born in England on this day in 1815, Boole grew up to become a mathematician. He came up with a kind of algebra we now call Boolean Algebra. The three most common operations of this kind of algebra are still used today in logic systems and even in Google searches:

AND

OR and

NOT.

Boole did not create the first computer. However, in hindsight he has been called the founder of computer science. Here's why:

In the 1930s an American named Claude Shannon and a Russian named Victor Shestakov both (separately) realized that Boolean Algebra could be used with electrical switches. Each switch has only two states: On and Off, or True and False, 1 and 0. The AND, OR, and NOT functions can be made into logic gates that serve as the foundation for the digital revolution.

Let's see how Boolean logic works. Say there are a lot of foods on a table: a ham sandwich, a green apple, a brownie, a banana, an orange, an Oreo cookie, a yellow cookie decorated with yellow frosting, and a white container full of plain yogurt. Which foods would you get with the following “searches”?

1. fruit AND yellow
2. fruit OR yellow
3. NOT fruit
4. NOT yellow
5. fruit NOT yellow
6. yellow NOT fruit

ANSWERS: 1.banana 2.apple, banana, and orange 3.sandwich, brownie, both cookies, yogurt 4.sandwich, apple, brownie, orange, Oreo, yogurt 5.apple and orange 6.yellow cookie

Learn more

• Here is a guide to how Boolean terms can focus or widen a search using a search engine. 

• I tried using the Boolean terms with Google and immediately realized that NOT doesn't work. Instead, I found out, you type a minus sign immediately before the term you want to exclude. Also, to be recognized as the OR operator, you have to type capital letters OR. 

• The web search tool Boolify makes it very clear which operator you are using.