What is fair use?

There is no clear-cut, widely accepted definition of fair use. According to copyright expert Georgia Harper of the University of Texas, fair use is described as "a shadowy territory whose boundaries are disputed, more so now that it includes cyberspace than ever before. In a way, it’s like a no-man’s land. Enter at your own risk." 

Basically, fair use allows you to use copyrighted works without permission of the author or creator as long as it is for an educational purpose. But, there's a lot more to it.

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Factors for determining fair use

Section 107 of the Federal Copyright Law (title 17, U.S. Code) describes fair use and lists some cases in which reproducing a work may be legal. These cases include criticism, reporting, education, scholarship, and research. Section 107 also describes four factors that are weighed when deciding whether or not a particular use is fair:

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

If a work is being used for a non-commercial use, for example education, the balance is tipped towards fair use. If the work is being used for a commercial purpose, like advertisement, the balance is shifted toward needing explicit permission.

(2) the nature of the copyrighted work

This refers to the type of the work in question. If it is a factual or scholarly work, as opposed to a creative or artistic work, it is more likely that it can be used without permission. Unpublished works are also more likely to require permission to be reproduced.

(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole

If a smaller or less significant portion of the work is being used, it is more likely to be a fair use.

(4) the effect of the use upon the potential market for or value of the copyrighted work

If the use makes the work less profitable or reduces the need for somebody else to purchase it, it is less likely to be considered a fair use.

These four factors are considered together, rather than individually. Thus, if a teacher photocopies an entire book for his or her students, it will likely not be considered a fair use even though it is for an educational purpose.