What are the most common operators?

The most common operators are:

• + (plus)
• - (minus)
• "" "(quotes) 

They are the operators that all the major search engines understand. 

These are also the operators that are most frequently used in queries. 

What does the + operator do?

The + operator tells the search engine to retrieve only documents that include the term it is used with. For example: +curriculum +english, will only return documents that have both of those terms. The + operator must be used before each term that must be included.  For example curriculum + english +science +art will return documents that have all the words curriculum, english, science, art.   Google and other search engines automatically add the AND operator between search terms. This makes the + operator unnecessary.  Most search engines treat + and AND the same way.

However, with search engines (such as AltaVista) that automatically insert OR between search terms, the + operator overrides OR and will only return documents that include the term.  For example, on AltaVista, curriculum english, will return documents with the term english OR curriculum. However +curriculum +english will return only documents with both terms.

What does the - operator do?

The - (minus sign or hyphen character) operator tells search engines to exclude documents that contain the term it is used with. Example: high school -curriculum would exclude any document with the word curriculum in it.

What does the " " operator do?

The " " (also called quotes) operator turns two or more individual terms into a single phrase that is searched for together and in order.  The quotes operator can also be used to tell some search engines to include words that they may normally exclude, such as a, and, the or other common terms as, for example, "to be or not to be."