Using a parameter it's possible to represent a property of an entire population with a single number instead of millions of individual data points. There are a number of possible parameters to choose from such as the median, mode, or interquartile range. Each is calculated in a different manner and illuminates the data from a different point of view. The mean is one of the most useful and widely used and helps us understand populations. A population is simulated by generating 10,000 floating point random numbers between 0 and 10. Sample means are displayed in histograms and analyzed.
Content Quality Concerns:
The page is very word-heavy; which makes it difficult for a novice student to digest. The applet lacks in customization and does not work on an iPad.
Content Quality Strengths:
Excellently written introduction that assumes no prior knowledge for the reader, but still will be useful for someone who has had a basic introduction to the material before. The applet is very nicely designed. The information on the web site provides a nice introduction to the reason this is important. Clear visualization with the graph of population and sample means on same screen.
Ease of Use Concerns:
The lack of customization makes the applet slightly less interactive. It would be nice if you could generate a custom distribution, rather than just the 4 defaults. Also, the student moves sliders to change sample size and number of samples. Students may not carefully read the information that shows change in number of samples and sample size. The use of the sliders makes it hard to be precise since the number of samples ranges from 1 to 4000 in the narrow space.
Ease of Use Strengths:
Very easy to use with excellent instructions, and includes some suggested steps to play with. The information on the web page provides sufficient information to use the applet, and the use of the population and sample means graph on the same screen makes it easy to visualize.
Potential Effectiveness Concerns:
The applet contains many numerical summaries; far more than the student is introduced to in the text. This may be confusing for a new student. Also, it does not seem possible for a faculty (or student) to know if the student understands the concept after using the applet since there is no assessment. The student may just "push the buttons." There are similar free applets available so it is somewhat redundant in addressing the concept.
Potential Effectiveness Strengths:
The article is very self-contained and a student could learn all the material on their own. The concepts are described both from a very intuitive level and a mathematical level, which can appeal to different types of students. As a self-contained object, it would be very easy to integrate into a class as homework to ease the lecture on the topic.
Potential Effectiveness Rating:
Source Code Available:
Source Code Available
Intended User Role:
Free for All