Fair Use is not a blanket “right", it's a legal defense. It developed out of a series of court cases before becoming codified in Section 107 of the U.S. copyright law. It allows copyrighted materials to used for teaching, criticism, comment, and news by analyzing four factors. You must meet more than a single factor to qualify for fair use, but you do not need to meet all factors. Copyright holders can challenge fair use at any time, but adhering to as many factors as possible will help the courts rule in your favor.

Four Factors

Purpose of Use – Includes commercial or nonprofit purposes, though non-commercial and educational purposes are preferred. Transformative use (using the work to create something new) is favored. Use of a work in a college workbook is not covered under fair use; permission should be obtained from the copyright holder.

• Example: Instructor used portions of works for a class presentation or lecture.

Nature of the Work – Factual works rather than creative works are eligible for fair use.

Amount and Substantiality of Portion Used – The smaller the quantity of content in relation to the work as a whole is more likely to be considered fair use. The amount should be appropriate for the intended purpose, i.e., only use the amount you need for the lesson or to fulfill pedagogical needs.

Effect of Use on the Potential Market or Value of the Work – Fair use is favored if you have legally acquired or purchased copies of the original work (library databases, subscriptions, interlibrary loan, etc.), you only make a small number of copies, and there is no licensing mechanism in place to prohibit such use. Fair use is prohibited if you use the works repeatedly for the long term and make them openly available online.

• Example of Fair Use: Using an article acquired from a library database for an assigned reading in a course. The library’s licensing agreement covers this type of use of within the institution.
• Not an Example of Fair Use: Instructor paraphrases and quotes large amounts of a textbook in a course packet s/he distributes to students online or in the classroom in place of a textbook.  This use will negatively affect the textbook’s sales. Including portions of works in an official course pack bought at a college bookstore may be allowed if permission from all copyright holders is obtained and they are compensated accordingly.