Power on X 1.6.5

Power on X is an easy to use program for calculating the statistical power of tests
Power on X is an easy to use program for calculating the statistical power of tests. Calculations can be a priori (performed on data derived from a pilot or previous studies) or post hoc where the data has already been derived. At present Power on X will perform power calculations based on one and two-tailed t-Tests of means or correlations

The calculator consists of a main calculation window in which the data can be entered and the type of test selected. In addition, an 'effect size' calculator is also included which can calculate 'effect size' from means and standard deviation, means and two standard deviations (requires sample size to be known), means and standard error of means (requires sample size to be known), and correlation. The registered version of Power on X is able to produce power and sample size tables for any given alpha value.

Main features of Power on X:

Written in Cocoa and therefore Mac OS X native

Calculate power for one and two-tailed t-Tests

Calculate power for t-Test of means and t-Test of correlations

Perform post hoc and a priori power calculations

Calculate power tables for any given alpha (significance value) and a range of sample size

Calculate sample size tables for any given alpha (significance value) and a range of power values.


Limitations of Power on X:

The demo version has a disabled table feature and a 'nag' screen.