The applets in our library are intended to illustrate concepts and techniques in probability and statistics in an interactive, dynamic way. You can download an applet, "drop" it into a web page (details on page 4), and then add other elements of your choice, such as expository text, data sets, and graphics. The PSOL currently contains approximately 60 applets that fall into two basic categories:

- Many of these applets are simulations of random processes, with the data displayed in custom tables and graphs. Typically, the student can vary the parameters of the process and choose among basic probability distributions that drive the simulation. The main goal of an applet of this type is to show the agreement between simulated behavior of the random process and predictions from the mathematical theory.
- In some PSOL applets, the student generates data by making choices in a game or by clicking on a number line or scatter plot. The main goal of an applet of this type is usually to increase the student's understanding of some statistical definition or concept.

In the next three sections we will consider a particular representative applet, the *Dice Experiment*, in some detail. My purpose is not to discuss the underlying mathematics, but rather the issues of *reuse* and *adaptability*.

Kyle Siegrist, "The Probability/Statistics Object Library - Applets," *Convergence* (October 2004)