The Java applets are designed to demonstrate the mathematical theory in a dynamic, interactive way. Each Java applet runs in a separate window, with the small amount of text necessary to describe the applet and its notation, but with little explicit mathematical exposition. Thus, the applets can be used with the expository portion of this project, or by themselves, at various mathematical levels.
The applets generally fall into two basic types:
To view the applets your browser must have the Java plug-in (version 1.5 or later) from Sun Microsystems. Click on the link or icon to go to the download area of Sun Microsystems. At this site, you can test your browser and download the plug-in, if you do not already have it.
A standard Graphical User Interface (GUI) is used, with command buttons, scroll bars and list boxes. There is no programming or command language, so students should be able to run the applets with little or no instructions. The applets run in a separate window, so that the student can easily move back and forth between the applets and the corresponding hypertext discussion, and so that a student can keep an applet open and running as she browses through the text. The following image show the Dice Experiment; click on the image to run the live applet.
The applet output is displayed numerically and graphically in a set of coordinated tables and graphs. A consistent color-coding is used. Graphical objects that depend only on the distributions or parameters are shown in blue, while graphical objects that depend on data (either simulation or student generated) are shown in red. Most applet objects have tool tips, small pop-up boxes that explain the object. Rest the cursor on an object to display the tool tip.
Applets that are simulations of random processes all have the Main Toolbar shown below:
The Main Toolbar has the following basic buttons and contorts:
The update frequency is selected from the first list box in the main toolbar. This number determines how often graphical and numerical displays are updated in run mode. In most applets, you can select an update frequency of 1, 10, 100, or 1000. In some applets, other update rules are provided. An update occurs automatically if the simulation is stopped by clicking the stop button.
The stop frequency is selected from the second list box in the main toolbar. The stop frequency is the number of runs before the simulation stops in run mode. In most applets you can select a stop frequency of 10, 100, 1000, or 10000. In some applets, other stop rules are provided.
The student can easily vary the parameters, select distributions, and choose among appropriate modeling assumptions using list boxes, scroll bars, and pop-up dialog boxes. These controls appear on parameter toolbars at the top of the applet window, below the main toolbar. All toolbars can be "undocked" into separate, small windows which can then be moved to a convenient place on the desktop. In particular, if some of the controls on a toolbar are not visible, undock the toolbar to reveal these controls. The following image shows the parameter toolbar of the Dice Experiment.