For example, one physlet, called Animator, can be used to create an infinite number of animations. In this way, the applet is general, and the teacher can script the applet for whatever specific purpose he or she has in mind. Pasted below is copied from CIP's web site. It is a preview of the article that will published in CIP about Physlets. Standard HTML form fields allow students to select parameter values in Physlet problems.
Students can then observe how the behavior of a simulated system changes.
The ability to control the behavior of Physlets through a scripting language enables authors to create a wide variety of physics problems out of a single applet. The use of Physlets allows teachers to ask questions that are different from traditional textbook problems. By using Physlets, teachers can avoid the pitfall of having the method of solving a problem suggested by the way the problem is written. When doing a Physlet problem, students are required to observe a motion, apply appropriate physics concepts, and make measurements before solving the problem mathematically. Students improve their understanding of physics concepts and of experimental error as well.