PP enables an instructor to rapidly and easily hand simulate many protocols, thereby concretely illustrating their operation. PP clearly displays the messages exchanged between client and server. The instructor generates client messages by clicking on buttons and filling in fields. Several years of classroom experience have demonstrated that PP helps students understand Internet application protocols. Many classrooms in affluent schools contain a network-connected podium computer with a projection display that the students can see.
Teachers use podium computers to teach computing by demonstrating software.
Unfortunately, such demonstrations often fail to teach fundamental ideas to students because the software is not designed for classroom teaching. Good software, by its nature, attempts to hide fundamental underlying ideas. Perceptually students have trouble visually tracking moving objects, such as a cursor or scrolling text. We believe that software designed especially for classroom teaching can dramatically enhance the effectiveness of instructors using podium computers. The design must consider both software engineering and perceptual psychology.