Fair use is a concept embedded in U.S. law that recognizes that certain uses of copyright-protected works do not require permission from the copyright holder. (See Title 17, section 107)

The following four factors are used to determine if a use is fair:

1. The purpose of the use (eg. commercial vs. educational)*
2. The nature of the copyrighted work
3. The amount of the material used
4. The effect of use on the potential market for or value of the work

* Not all uses in an academic context are automatically considered fair use!