Gallery of Applets
Welcome to the gallery of BolderStats applets. These Java applets were prepared for
instructional use
in statistics classes at the University of Colorado. They are not intended for statistical
calcuations. Instead, they illustrate various statistical principles. Direct interaction with
the applets allows students to better understand the underlying statistical principles.
All applets demonstrated here use the charting, mathematical, and statistical class files
of Visual Numerics' JMSL™ Numerical Library for Java™
Applications. If you have any trouble with the applets, check
Browser Notes for tested browsers and operating systems as well
as necessary plug-ins.
Click on the links to the left to see each applet. The page displaying each applet provides
explanation and instructions on how to use the applet. Below are brief descriptions of each applet
with a link. Click on the "Home" link or use your browser's Back button to return to this
page.
Correlation and Regression Applet
- CorrelationPicture--change the degree of organization in a
scatterplot and observe the corresponding change in the correlation coefficient or, optionally,
the least-squares regression line.
- CorrelationPoints--click on the graph to add data points; the
correlation coefficient and, optionally, the least-squares regression line update.
- RegFit--dragging the slope of the regression line changes of the
sum of squared errors and allows finding the least-squares regression line graphically.
- TaylorRussell--An interactive version of the Taylor-Russell
diagram illustrates the effect of making selection decisions with an imperfect predictor
variable.
Binomial Distribution
- BinomCalc--displays binomial probabilities for individual
counts or for ranges of counts.
Normal Distribution
NormalShapes--illusrates the effects of changing the parameters of
the mean and the standard deviation for the normal distribution.
- NormalProb--a graphical interface for calculating probabilities for
the normal distribution.
- NormalHandle--a more interactive applet for computing normal
probabilities.
- DensityCDF--illustrates the relationship between probability density
and distribution functions using the normal distribution as an example.
- CohenD--illustrates the meaning of the effect size measure Cohen's
d in terms of overlap between two normal distributions.
Correcting Conceptual Misunderstandings
Applets are very useful for helping correct common data analysis misunderstandings. Below are
two examples.
- MedianSplit--illustrates the expected deleterious effects of
dichotomizing a continuous variable at its median.
- ModeratorExplain--illustrates the meaning of the various parameters
in a moderated regression model and allows user to observe changes in those parameters with
different scalings of the predictor variable.
- QuadraticExplain--illustrates the meaning fo the various parameters
in a quadratic model and allows user to observe changes in those parameters with different
scalings of the predictor variable.
© 2004, BolderStats LLC
For more information, contact
Gary.McClelland@Colorado.edu