“Copyright is a legal device that provides the creator of a work of art or literature, or a work that conveys information or ideas to control how the work is used.”The intent of copyright is to advance the progress of knowledge by giving an author of a work an economic incentive to create new works.
Copyright provides authors fairly substantial control over their work, although in order to publish their works many authors assign those rights to their publishers. The four basic protections are:
Fair use is a doctrine in the law of the United States that permits limited use of copyrighted material without having to first acquire permission from the copyright holder. Fair use is the most significant limitation on the copyright holder's rights. Deciding whether the use of a work is fair IS NOT a science. There are no set guidelines that are universally accepted. Instead, the individual who wants to use a copyrighted work must weigh four factors:
The purpose and character of the use:
The nature of the copyrighted work:
The amount and substantiality of the portion used:
The effect of use on the potential market for the copyrighted work:
This is the factor that has changed how fair use is interpreted by publishers and by the courts. For example, the ability to easily find publishers addresses and copyright contact information on the internet, means that the "one semester without permission rule" is much more strongly enforced, and taken much more seriously by the courts. Another example, the ability to sell electronic copies of material over the internet means that publishers see almost any use as impinging on all potential markets.