Fair use is a broad, flexible, nonspecific exemption that allows individuals to use copyrighted works without permission from the copyright holder under certain circumstances. The purpose of the use can include "criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research." But just because you're using a work for educational purposes does not automatically make the use a fair use; there are four factors to consider when making a fair use determination.
|Factor||Fair Use||Not Fair Use|
|Purpose & character of the use||
|Nature of the work||
out of print
(both qualitative and quantitative)
|Just enough to prove your point||
a lot of the work;
the heart of the work
|Effect on the market||No effect||
Replaces the need to buy the work;
hurts the market for potential derivatives
Source: 17 U.S.C. §107
To decide if a use is a fair use, you will need to consider where your intended use falls for each of the four factors. Imagine that you have a scale and you're trying to get the fair use side to be heavier than the side that's against fair use. If you have 3 or 4 of the factors in favor of fair use, then it's pretty safe to say that your use is fair.
But what if you have 2 factors for fair use and 2 against? This is where fair use determinations get tricky; it is best to use your best judgment and understand that there are legal risks involved with your decision.