Think of the effects on students' willingness to respond to teacher-posed questions when statements such as the following are made:
• "Since I have explained this several times already, you all should know what is the effect of an increased demand upon this supply curve."
• "Obviously, when you use this formula you'll get...?"
• (After having listened to several students' answers) "The real answer is this:"
• "Does everybody understand the explanation I just gave? It should be clear by now."
• "O.K. Now rephrase your answer the way you think I would say it."