Section 107 of Title 17 of the US Code (see http://www4.law.cornell.edu/uscode/17/107.html), stipulates one type of limitation on the exclusive rights of the copyright holder, of particular interest to educators: fair use.
The statute relies on four primary criteria (shown below). The exact nature of how to interpret these four factors has been the subject of widespread national and international debate, policy development, and treaty for years, often with little agreement arising between the publishing and the library communities, the technology-exporting and technology-importing nations, et cetera. For a sampling of some of the debate, the reader might search the cni-copyright forum which contains (as of August 1999) 4026 postings discussing fair use.
Relevant to developing material for distribution on the World Wide Web is one area in which many experts seem to agree in interpreting the statute:
It is a fairly brief statute and is copied here (April 14, 1999) from
http://www4.law.cornell.edu/uscode/17/107.html.
Sec. 107. Limitations on exclusive rights: Fair use
Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include -