When a court is decideing if the use made of a particular work in any case is fair use, there are four factors that need to be taken into consideration.  They are:

1. The purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes.

2. The nature of the copyrighted work.

3. The amound and substantiality of the portion used in relation to the copyrighted work as a whole; and

4. The effect of the use upon the potential market for or value of the copyrighted work.