It's a feedback mechanism that's been around for some time. Most often used during a course, students are asked to fold a sheet of paper in thirds and label the columns stop, start, and continue. Then they are asked to identify aspects of instruction that the teacher should stop doing, things they'd like the teacher to consider doing, and those practices they'd recommend that the teacher continue doing. What they identify in each area should be instructional policies, practices, or behaviors that relate to their learning experiences in the course.