Each of these has advantages and disadvantages. Java applets often implicitly guide students along a set path. In this case the set path is the investigation of projection when the slide and the screen are parallel to each other. With graph paper, pencil, and paper students can explore ordinary projection more broadly. Java applets often help keep students "on task" and, typically, they are often quicker. It is important that we use a mixture including both dedicated tools like Java applets that are easy to use and keep students on task and more open-ended tools like graph paper, pencil, and paper taht allow students more freedom and that help them develop skills that will be useful in other circumstances.
