Expands the Capabilities of SPSS and Excel 

Program Dynamic

This program asks the user to input the number of levels of each factor and the type of contrast to focus on.  In the example below, the user chooses to do a power analysis on a simple main effect comparing two levels for Factor A at a given level of Factor B.  The user specifies an effect size and the population standard deviation.  In this example, the entries are designed to evaluate a medium effect size as defined by Cohen (which maps onto a d statistic of 0.50).  The user also specifies a sample size to evaluate.  For a sample size of 65 per group, the statistical power for a simple main effect comparing two levels of A at a given level of B is 0.8105. 

The horizontal bar beneath the sample size box can be clicked to conveniently and quickly change the sample size.  ZumaStat provides an instantaneous update to the power value with each click on the horizontal bar.  It is very easy to see how power changes with different sample sizes. 

The program is unique in that few statistical packages provide power analysis for more focused contrasts in analysis of variance.  ZumaStat does power analysis on all of the most common tests in ANOVA (as well as tests for correlation, regression, logistic regression and percentages), at a fraction the cost of existing software. 

How it Appears on Your Screen