“Being classes,” as the authors refer to them, rest on the belief that students themselves control what they are learning. Teachers cannot learn content for students -- that one’s easy. But neither can teachers force students to learn what they are teaching. From any given learning experience, students will take vastly different things. They learn in different ways and filter all learning experiences through the unique set of past experiences. If you doubt these premises, the authors challenge you to take a learning experience that has occurred in your class, maybe a good student presentation, an exercise or an especially animated discussion, and immediately after its conclusion, ask students to write a paragraph about what they learned.