The Greek philosopher Socrates taught his students by question and answer sessions. He might begin a lesson by posing a simple question, for example, and let the student arrive at the moral of the lesson himself. Socrates believed that this was the most effective way to impart knowledge, in part because it could teach the teacher many things while also teaching the students.
Debate has a number of advantages compared to lecturing a class. For one, it dependably maintains students' attention for longer than lecturing. By engaging the students directly, they become part of the discussion, whereas lecturing only teaches at students. When students are actively engaged as such and a part of the discussion, they hold the information or lesson they're taught much better. Debate also provides a platform for students to express themselves and can help boost students' confidence and public speaking skills.
Sometimes discussion, however, can range too far from the topic of the lesson and become unfocused. If this happens, discussion can be a waste of class time. Worse, if the discussion never quite solves a problem, or if many possible answers arise to a problem, students can leave a class session more confused than edified. They might also become unruly or disrupt the teacher's control over a class and undermine a teacher's credibility among the students. In addition, if a few students are more comfortable being vocal, and a other students are shy, the louder students may drown out the other students.
Teachers leading a discussion in the classroom should direct the discussion in a way that ensures the students do not venture too far astride of the topic at hand. Likewise, in the case that many answers are vocalized, the teacher should pause the discussion and provide insight to clear up any residual confusion among the students. To begin the discussion, teachers can ask open-ended questions to stimulate the students' engagement.