In this month's fair use question a PhD candidate is given a chance to publish, but is concerned his use of quotes might invite a lawsuit.
I’m a PhD candidate in film theory. My paper on the depiction of mental health in Hollywood has been accepted by a journal. But I quote at length from dialogue in several films.
I sure don't want to make enemies this early in my career--especially at the studios. Am I in the clear? Would fair use apply here?
You want to see if your use accords with the expectations of film scholars and communication scholars, both of whom have created codes of best practices in fair use. Both communities of scholars assert their fair use rights to refer to popular culture in the process of scholarly analysis.
For instance, Situation One of the Code of Best Practices in Fair Use for Communication Research, created by the International Communication Association and facilitated by the Center for Social Media and the Washington College of Law at American University, finds fair use eligible in “analysis, criticism and commentary.” The limitations? The Code asserts: "A scholar should determine the extent of use based on the scholar's analytic objective" and "not employ more than is needed for the scholarly objective, either to conduct the original research or to explain it to others." Scholars also expect that you will cite the original work correctly.
So you yourself need to decide how much of the dialogue is OK to use without permission, based on your analytic objective and how much you need to use to achieve that objective.