In chapter four of Levin and Nolan, they briefly mentioned four power bases: referent, expert, legitimate, and reward/coercive. Referent is when the students and teacher have a mutual relationship of liking each other. Expert is when the students feel they can learn from the teacher, because they are so knowledgeable. Legitimate is when the teacher is the main authority in the classroom. I view this as the typical power in a classroom. Finally, reward/coercive is when the students receive some type of reward, and in return the teacher gains authority through the rewards.
I chose to represent Assertive Discipline (AD) with the above picture, because with AD there are multiple ways to handle student(s). As you can see in the picture, there are students behaving in the desired behavior, and a couple that aren't. The teacher will have to use different methods with different students.