Fair Use provisions were placed in the copyright law to ensure a balance between the rights of copyright owners and the public interest...particularly for educational purposes. Fair Use allows certain people (educators, newspaper opinion writers, critics) the ability to use copyrighted works without permission when the evaluation of the use is considered "fair."
This is where things get a bit tricky, however. The lawmakers who created the copyright law and provisions wanted to ensure that the law would remain stable over time. Therefore, they created a set of fair use guidelines rather than a set of clearly spelled out rules. Educators who wish to claim "fair use" should be fully aware of the guidelines and stay alert to changes in the interpretation of the copyright law.
Yes. Works in the public domain are not protected by copyright. Works in the public domain include works where the copyright period has expired or works that were created by the U.S. Government or by its employees. For example, materials posted on any U.S. Government web page (for example that of the U.S. Copyright Office) are in the public domain and can be copied freely.
See the following resources to help determine if a work is in the public domain:
There are four guidelines that should be considered to determine if educational use of a copyrighted work is considered "fair":
Weighing fair use is much like using a scale. Cases are judged based on whether the total of these factors leans toward fair or unfair use. If there is any doubt, ask for permission to use the materials.
For more resources on Fair Use for Education, see the following links: