November 2 – From Boole…to Google?

November 2, 2021

Posted on November 2, 2021

This is an update of my post published on November 2, 2010:

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 computer science, 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.

If you search for puppy AND kitten, you will only get pages that include both words.
If you search for puppy OR kitten, you will get pages that either one or both words.
If you search for puppy NOT kitten, you will get pages that include the
word “puppy,” but do not include the word “kitten.”

So AND and NOT limit and focus your search.
OR widens your search.

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”?

fruit AND yellow
fruit OR yellow
NOT fruit
NOT yellow
fruit NOT yellow
yellow NOT fruit

ANSWERS:

1. banana

2. apple, banana, orange, yellow cookie

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 quickie 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 does not 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.