An “Agreement on Guidelines for Classroom Copying in Not-For-Profit Educational Institutions with respect to books and periodicals” (1976) -- the result of deliberations between Congressional and publisher representatives -- stated “the minimum and not the maximum standards of educational fair use under Section 107….” (See Office of Copyright, Circular 21, “Reproduction of Copyrighted Works by Educators and Librarians” (Page 6).)
Though some interpret these to be specifications for fair use, it should be noted that they were expressly designated as “minimum standards.” Further, these reflect “guidelines” and do not constitute copyright law. They do not represent directly applying the four fair use criteria to a specific case. The fair use doctrine inherently entails flexibility both in its applications to specific instances and as technologies, circumstances, and contexts evolve.
One avenue for using copyrighted content is to seek permission from the copyright holder. It is a good idea to think through the four fair use criteria before making a permission request because a positive fair use judgment may be determined. Permission for use by the copyright holder trumps an individual assessment about fair use.
However, a permission request may be denied, in which case it would not be prudent to make use of that content under the guise of fair use. Should you wish to seek permission, here is a model permission request letter (from Duke University):