| APPLET | SOURCE | DESCRIPTION |
|
| Double Sample and Detect Difference | Univ. of Utah, StatCenter (Malloy, Jensen) | "Double Sample" allows user to explore differences in t statistics when two samples are drawn from either the same or different normal distributions, "Detect Difference" allows user to generate multiple examples with two samples from which they must guess whether they came from populations with the same or different means based on the t statistic (easy, medium and hard examples can be chosen). more |
| Two sample hypothesis test | Java Applets for the Visualization of Statistical Concepts (VESTAC) | Generates a specified number of samples (shown visually) to illustrate the effects on the p-value of the test for two independent means as users vary hypotheses about the means as well as the sample size, variance, significance level and true population means. more |
| Hypothesis Testing: T-tests | Monash Univ. Business and Economics (Stewart, Bernal-Melo) | Simulates data to show the effects of population means and standard deviations and sample sizes on test statistics, p-values and results of independent or paired samples tests, shows scatterplot and graphical display of rejection regions/p-values. more |
| Power of a Test | W.H. Freeman & Co. | Shows graphically alpha and power as user adjusts hypotheses about a mean, sample size, standard deviation, significance level and alternative population mean. more |
| Hypothesis Testing Applets | Statistical Java (Dorai-Raj, Anderson-Cook, Robinson) | Shows the effects on the critical value and power of a test for a mean when the sample size, significance level and/or difference between the means of the null and alternative distributions are adjusted. more |
| The Power of a Test Concerning the Mean of a Normal Population | Wolfram Demonstrations Project | For 1- or 2-tailed tests for a mean, graphically shows effects of changing actual mean, population mean and variance and sample size on significance level and power. Requires download of Mathematica Player as well as demo itself, good for classroom demonstration. more |
| Hypothesis Testing Power Applet | Ogden | Short expository material plus applet that shows graphically alpha and power for 1- and 2-tailed tests for a mean based on user entered population parameters, sample size and hypothesized mean. more |
| Factors that affect power | Seeing Statistics (McClelland) in Fundamental Statistics for the Behavioral Sciences (Howell) | Shows with graphs how power is affected by changes in the alternative mean, sample size and population standard deviation. more |