The devices package contains Java objects with visible interfaces. These fall into four basic categories:

• Physical objects, including coins, dice, cards, spinners, and other sampling objects.
• Graphs, including histograms, scatterplots, timelines, and special graphs of probability density functions, empricial density functions, and cumulative distribution functions.
• Tables, including special tables for displaying the outcomes of random experiments, probability distributions, and empirical distributions.
• Interface objects such as custom scrollbars, buttons, and dialog boxes.