"Computers are useless. They can only give you answers." --Pablo Picasso
Since the Web is not organized in the same way a research database is, you usually cannot do field searching on the Web nor can you rely on the consistency of a controlled vocabulary.
Computerized search mechanisms are based on Boolean logic. When you use the enter code words known as boolean operators you are telling the computer exactly how to perform a search which will be tailored to your specific needs.
The most commonly used code words are: AND, OR, and NOT. The phrase you enter into a search box is called the search string (or syntax)
|Operator||Description||Possible Search Strings||Example|
|AND||This operator combines the individual words (terms) in order to create a more specific search. It NARROWS your search.||
cats AND dogs
|OR||This operator combines possible synonyms of the individual words in order to create a wider search. It BROADENS your search.||films OR movies OR motion pictures|
|NOT||This operator limits (reduces) your search results by excluding specific terms. It NARROWS your search.||
dolphins NOT football
You can also combine these searches using parentheses. For instance, to look for non-toy dog , try:
The use of quotation marks is a handy device to cause the computer to search for the exact phrase. For instance:
If you are not sure of the spelling, or want to search variants, use a question mark ? or an asterisk * as wildcards:
Different search engines and research databases incorporate Boolean logic in different ways, but they all use it. Some assume AND, some assume OR. It is important to read the instructions for each search engine before entering your search terms.