In Figure 3, we compare the profiles of students' and teachers' responses to the same three questions. In both groups approximately the same percentage get the answer correct, but the distributions of wrong answers is different. Many more teachers than students believe that the oil has no effect on the position of the object. The Classtalk system consists of a central instructor's computer networked to a number of small palm-top computers, each of which is typically shared by two to four student users. The instructor makes up questions and tasks, usually before class, and governs the use of the entire system during class.
Students respond individually or in groups.