The name 'Boolean' came from a gentleman name Boole who worked out "an algebraic system of logic" that ended up being useful for talking to computers roughly a century later.

All you need to know, though, is that it's also useful for talking to database search engines. And it's easier than it sounds, especially because database interfaces have been deliberately designed to make it so.

The 3 basic Boolean operators, and what using them tells the database search engine to do

AND - Tells the database that both words on either side of the 'AND' have to be in the search results

OR - Tells the database that one or the other word on either side of the 'OR' needs to be in the search results - you'll take either, you'll take both

NOT - Tells the database that the word right after 'NOT' must not be in your search results

To do an 'AND' Seach:

Easiest way is to:

• Go to the database 'Advanced' search page
• You'll see multiple (usually 3) search boxes and ways to add more if needed
• Type one search word in each open box
• Run search
• Congratulations! You've just run a Boolean 'AND' search - which happens by default in the advanced page every time you use more than one search box.

To do an 'OR' search:

You can choose between the 3 connectors in a pull-down menu right next to the start of each search box. However, since most people use Boolean 'OR' when they want to find synonyms of a search word, I suggest this:

• On the advanced search page type a search word in each empty box
• Then, in the search boxes containing a search word that you want to search for that you KNOW has synonyms, add a capital OR, then a synonym of the first search word, in that same box. Don't do anything else in that box,except add an OR and any other synonym you have, until it looks something like this:
  • word OR synonym OR synonym OR synonym
• Then just run the search
• Congratulations! You've just used Boolean 'OR' to search for several synonyms for that search word / concept

To do a 'NOT' search

Be careful with this one - most people don't have to use 'NOT', and it's easy to cut out a lot of results that might have been useful.

The situation in which a searcher might want to use 'NOT' is when the results are a mix of good ones, but the rest are appearing because one of your search words might mean something specific, but in another discipline than the one you need results from - and it's annoying the heck out of you; you want to see if you can cut out that specific, 'incorrect' subset of results.

As a hypothetical example...say you're looking for Nursing articles, and are using a specific term or acronym that you feel you HAVE to use...and it coincidentally means something different in Engineering research! You may be able to cut out at least some of the unwanted engineering articles by doing the following:

• Type your search into the several search boxes
• Choose 'NO' from the Boolean pull-down menu on the Advanced search page
• Type a different search word or phrase in the search box that you know WON'T appear in Nursing articles, but WILL be in the engineering articles
• Run the search
• If you see that the out-of-place engineering articles seem to have disappeared (and you don't think you lost any of the Nursing results), Congratulations! You've successfully pulled off a tricky 'NOT' Boolean search.