Rice Virtual Lab in Statistics

Simulations/Demonstrations

Compatibliltiy note:
These simulations all requre a browser that supports Java. Most of them require a browser that supports version 1.1 of Java. Internet Explorer 4.0 supports Java 1.1. Netscape Navigator/Communicator 4.04 supports Java 1.1 only if you add a software patch. A preview release of version 4.05 supports Java 1.1.

Rice Virtual Lab in Statistics

Email comments and/or suggestions to lane@rice.edu.

Grant No. DUE-9751307

  Mean and Median
Requires a browser that supports Java 1.1
This applet demonstrates basic properties of the mean and median including (a) the effect of skew on the relative size of the mean and median, (b) the mean deviation from the mean is zero, and (c) the mean squared deviation from the mean is less than or equal to the mean squared deviation from the median (or any other number).

Sampling Distribution Simulation
Requires a browser that supports Java
This applet estimates and plots the sampling distribution of various statistics. You specify the population distribution, sample size, and statistic. An animated sample from the population is shown and the statistic is plotted. This can be repeated to estimate the sampling distribution.

Normal Approximation to the Binomial Distribution
Requires a browser that supports Java 1.1
This demonstration allows you to view the binomial distribution and the normal approximation to it as a function of the probability of a success on a given trial and the number of trials. It can be used to compute binomial probabilities and normal approximations of those probabilities.

Components of r
Requires a browser that supports Java.
The slope, standard error of the estimate, and the standard deviation of X can all be manipulated independently to see the effect on the scatterplot and on r.

Regression by Eye
Requires a browser that supports Java 1.1
A scatterplot is displayed and you draw in a regression line by hand. You can then compare your line to the best least squares fit. You can also try to guess the value of Pearson's correlation coefficient.

Restriction of Range
Requires a browser that supports Java 1.1
The range of X can be manupulated to investigate its effect on Pearson's r and other aspects of the relationship between X and Y.

Repeated Measures
Requires a browser that supports Java 1.1
This applet lets you investigate differences between correlated and independent t tests.

A "Small" Effect Size Can Make a Large Difference
Requires a browser that supports Java.
This applet demonstrates that even a "small" effect can be important under some circumstances. Applicants from two groups apply for a job. The user manipulates the difference between groups on the variable on which selection is made and the cutoff for hiring. The effects on the proportion of hired applicants from each group are displayed. A related phenomenon is discussed in the article:

Martel, R., Lane, D. M., & Willis, C. (1996) Male-female differences: A computer simulation.
American Psychologist, 51, 157-158.


Normal Approximation to the Binomial Distribution (Old Version)
Requires a browser that supports Java.