Under the “fair use” rule of copyright law, someone may use part of another author’s work without asking permission. Fair use is intended to support teaching, research, and scholarship, and others' individual creativity. However, “fair use” is not defined by statute and is therefore wide open to interpretation.
In using part of someone else's work, invoking fair use becomes a good-faith assertion on your part. How much of someone else's work is really only "fair" when a judge says it is in a legal decision. You don't want to be sued for infringement just to find out for sure your use was legally fair, so be careful how you use others' work. Keep in mind that "educational use" alone does not make use of a work fair. It is always important to analyze how you are going use a particular work against the following four factors of fair use. Here is what the law says:
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—
U.S. Copyright Office provides a fact sheet
University of Texas provides a summary of Fair Use.
Fair use is a doctrine of US copyright law that allows limited use of copyrighted works without seeking permission. Fair use is typically invoked for criticism, comment, news reporting, teaching, scholarship, and research.
The law specifies a "four-factor test" to determine if a use is fair. You can do the same:
Guidelines are not hard rules, they just help you decide how you might use material without permission.
Guidelines for Distributing Photocopies
Guidelines for Using Materials Found on the Internet
Guidelines for Using Multi-Media
Multimedia works are created by combining copyrighted media elements such as motion media, music, other sounds, graphics, and text. It is recommended that you use only small portions of other people's works.
What is considered a small portion? (these amounts are not rules for determining fair use)
The following guidelines allow you to use multimedia without permission of lawfully acquired copyrighted works.
Code of Best Practices in Fair Use for Media
The Center for Social Media in the School of Communication at American University, the Program on Information Justice and Intellectual Property in American University Washington College of Law, and the Media Education Lab of Temple University are conducting a project 2007-2009 to clarify fair use in media education, with support from the John D. and Catherine T. MacArthur Foundation. This project will help media literacy educators understand their rights under the doctrine of fair use in order to help them more effectively use media as an essential part of their teaching.