Ribbon bar. Select the Statistics tab. In the Advanced/Multivariate group, click Power Analysis to display the Power Analysis and Interval Estimation Startup Panel.

Classic
menus. On the Statistics
menu, select Power Analysis

The Startup Panel contains one tab: Quick.

See also the Power Analysis Index, Overviews, and Examples.

Analysis category.
Select the analysis category you want to use from the left pane
of the tab.

Power Calculation. Select Power
Calculation to calculate statistical power for a given analysis
type (selected from the box on the right), and to produce graphs of power
as a function of various quantities that affect power in practice, such
as effect size, type I error rate, and sample size.

Sample Size Calculation. Select Sample Size Calculation to calculate, for a given analysis type (selected from the box on the right), the sample size required to attain a given level of power, and to generate plots of required sample size as a function of required power, type I error rate, and effect size.

Interval Estimation. Select Interval Estimation to calculate, for a given analysis type (selected from the box on the right), specialized confidence intervals not generally available in general-purpose statistical packages. These confidence intervals are distinguished in some cases by the fact that they refer to standardized effects, and in others by the fact that they are exact confidence intervals in situations where only approximate techniques have generally been available.

Probability Distributions. Select Probability Distributions to perform a variety of calculations on probability distributions that are of special value in performing power and sample size calculations. The routines are distinguished by their high level of accuracy, and the wide range of parameter values for which they will perform calculations. The noncentral distributions are also distinguished by the ability to calculate a noncentrality parameter that places a given observation at a given percentage point in the noncentral distribution. The ability to perform this calculation is essential to the technique of "noncentrality interval estimation" (Steiger and Fouladi, 1997).

Analysis Type. From the right pane of the tab, select the type of analysis you want to conduct for the selected analysis category. Note that the analysis types available in this box depend on the analysis selected in the left box. For information, see the following analysis categories: Power Calculation, Sample Size Calculation, Interval Estimation, and Probability Distributions.

OK. Click the OK button to display the analysis specification dialog box associated with the analysis category and type specified on the Quick tab.

Cancel. Click the Cancel button to close the Startup Panel without performing an analysis.

Options. See Options Menu for descriptions of the commands on this menu.