Many new teachers spend a very restless Sunday night. In all likelihood they are thinking of what happened last week, or what they might do in class on Monday morning when the bell rings, the kids pour into the classroom, the door is shut, and the lesson begins. In fact, new teachers spend a great deal of time thinking about their practice. While driving on the highway, and in supermarket checkout lines, they ponder, “How to get Juan to write?” or “How could I have handled that fight in the hallway better last Thursday?” or “How can I best present dividing fractions to a remedial math class?” The search for a satisfactory lesson is particularly acute for new teachers.