This site, authored by David M. Lane of HyperStat Online, explains the relationship between hypothesis testing and confidence intervals. Because of the immense similarities between the two procedures many find them to be...

Validation of psychological tests has not yet been adequately conceptualized, as the APA Committee on Psychological Tests learned when it undertook (1950-54) to specify what qualities should be investigated before a test...

The Real World Learning Objects Library presents a mathematical problem couched in real-life examples for this examination of prisons within a mathematic context. Students consider the business model of a prison, status...

These applets, created by Virginia Tech's Department of Statistics, allow you to see how the common Xbar control chart is constructed with known variance. The Xbar chart is constructed by collecting a sample of size n at...

This applet lets you take "slices" through a multivariate data set to compare the distribution of a variable without regard for the values of the other variables with the distribution of that variable when the value of...