Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Boolean Searching Tips: Using AND, OR, NOT

Searching tips and techniques for higher-level students. Advanced searching techniques to ensure retrieving all possible information.

Keyword searching using AND, OR, NOT

Keyword searching using keywords allows you to search for single words or phrases, combinations of words and phrases.

In searching using keywords avoid using prepositions such as (the, of, to), and avoid using three special terms they are (and, or, not) these special terms will be used in conducting the search to get better results.

To get the best results from your search you have to know how to do a keyword search it is invaluable for finding material on multi- disciplinary subjects which cannot be defined by searching one single word or phrase.

Boolean search:

Boolean search method was developed by George Boole, a nineteenth Century mathematician.

Boolean searching can be used to define a topic very specifically, so that you can find what you need easily.

Keyword searching using AND

If you are searching for a very general topic that can be difined with only one word or phrase you don't need to use the boolean search.

If you are trying to search using more than one word or phrase you can use one of the principles of boolean logic

Using AND

If you are searching for an article or study about energy and global warming.

 Using OR

The boolean expression OR broadens your search. You will retrieve more items.

Your search result will contain all sources about energy and global warming.

When you use OR between search terms, you specify that items must contain one term or the other, but they don't need to contain both.

 

 

Using NOT

Using NOT will narrow your search.

The searching word NOT isn't used as often as AND or OR - use it with care so that you don't exclude useful material by mistake.

You can use NOT to eliminate irrelevent terms or items retrieval.

We can do a search for energy AND global warming NOT solar energy, in this way we are excluding all items with solar energy.