Boolean logic links ideas in order to narrow or expand a database search by using the operators AND, OR, or NOT. Systems that use boolean logic ask that you type in keywords linked by these operators. You can picture the logic behind these operators through Venn diagrams.
AND narrows your search. This operator retrieves items that contain all of the linked words. For example: distance AND training AND performance, would bring up articles that must contain all three words. The shaded region in this Venn diagram represents the articles that contain all three words.
Distance AND Training AND Performance
Even though AND limits your search you may still call up irrelevant articles. For example; the above search may turn up articles on improving your performance at distance running when you are really interested in educational technology topics. The NOT operator eliminates unwanted retrievals. For example; distance AND training AND performance NOT running prevents the search from returning articles concerning running. The shaded region in this Venn diagram represents articles retrieved by this search:
Distance AND
Training
AND
Performance
NOT
Running
AND and NOT work at limiting your search. What if you want to expand you search? OR links terms that may appear in relevant articles. For example; training OR education would return articles containg either (or both) of these words. The shaded region in this Venn diagram represents articles retrieved by this search
Training OR Education
To limit the above search to articles that must contain the word distance , and may contain either education, or training you would write: education OR training AND distance.
Education OR Training AND Distance.
On to the activity.