This applet simulates rolling dice and displays the outcomes in a histogram. Students can choose to roll 1, 2, 6, or 9 dice either 1, 10, 20, or 100 times. The outcome studied is the sum of the dice and a red line is drawn on the histogram to show expected number of occurences of each outcome.
Java capable browser
Content Quality Concerns:
The histograms would be much more effective if a labeled x-axis was included. It is not very clear what the horizontal line represents, so a labeled y-axis would be beneficial. Some thought questions for the students would be good to lead them to think about the main ideas. Ask them about short-run vs. long-run results.The explanations of terms and the applet in general are vague and written in poor English/mathematical terminology. For example, the author says "the red plot shows". He/she means the 'red line'. There should be a clearer explanation as to the difference between a probability histogram and a sample histogram -- it would be nice if the author would display the probability histogram alongside the sample histogram in each case -- or explain that his 'expected number of occurences' is essentially that. There is no explanation that the die show the last roll -- which is bound to confuse students.
Content Quality Strengths:
The graphics are nice, large and clear, and the applet works well and quickly.
Ease of Use Concerns:
Again, using the applet is not enough. The student needs to have a better understanding of what information the histograms provide. The horizontal bar on the histogram is not clearly explained.
Ease of Use Strengths:
There are no problems with using this applet -- it's obvious how to use it and it works just fine.
Potential Effectiveness Concerns:
A student would have a hard time knowing what the histograms mean, and a student also might not understand what the goal of using the applet is. Some additional guiding questions could make this applet much more effective. This might not be a good in-class demonstration--the details might be hard to see on a screen. It would be easier to have students roll dice themselves and create a histogram in class than to explain what this one is trying to show.
Potential Effectiveness Strengths:
The user can quickly see how distributions change for rolling up to 9 dice at once.
Potential Effectiveness Rating:
Source Code Available:
Source Code Available
Intended User Role:
Free for All