Can someone please explain Boolean search logic to me?

Question

And how I can use it with Google

Answer 1

Google said they've changed their site to automatically do boolean searches, but I doubt it. Here's the gist of it, it's fairly easy to do, and hopefully I've explained it clearly.

1. When you type in two keywords, Google searches for pages containing either or both words. Example:

[ china dolls ]
Returns:
- any pages containing "china"
- any pages containing "dolls"
- any pages containing "china" and "dolls"
- any pages containing "china dolls"

2. If you put a plus sign ("+") before a keyword, then the word _must_ be included in the results. Example:

[ +china dolls ]
Returns:
- any pages containing "china"
- any pages containing "china" and "dolls"
- any pages containing "china dolls"

[ +china +dolls ]
Returns:
- any pages containing "china" AND "dolls" (but not as a phrase)
- any pages containing "china dolls"

3. If you put quotations around keywords, then the words will be matched exactly. Example:

[ "china dolls" ]

Returns:
- any pages containing "china dolls" as a phrase

4. Phrases can also be used as keywords with a plus sign ("+"). Example:

[ +"china dolls" +music +Thailand ]

(Look 'em up. ^_^)

5. A minus sign ("-") can be used in the same way to _exclude_ results. Example:

[ +china -dolls ]

Returns:
- any pages containing "china" but NOT containing "dolls"


.

Answer 2

There are 3 primary Boolean logic operators: AND, OR, and NOT. AND narrows your search, OR broadens your search, and NOT is used to exclude concepts

This site explains more:
http://www.apa.org/psycinfo/training/boolean.html

Answer 3

It is explained nicely on the link I provided but in a nutshell a plus sign (+) means it HAS be be found in the search and a minus sign (-) means exclude, or return search options which do not contain this word