From Diversifying Economic Quality: A Wiki for Instructors and Departments
One-minute paper is a teaching strategy where students are asked one or two deep questions about the material covered. Angelo and Cross (1993) suggests questions designed to encourage critical thinking and not regurgitation of information. A Berkeley Compendium of Suggestions for Teaching with Excellence state that one-minute papers allow you to "Know if the class is understanding you or not, know if students are bored or confused, encourage students to listen actively during lectures, [and] give students experience writing short essay answers." Read here for more information.
Here is an example of a one-minute paper from Tufts University.
Angelo, T.A. & Cross, K.P. (1993). Classroom Assessment Techniques (2nd ed.). San Francisco: Jossey-Bass Publishers.