1-Way ANOVA: Sample Size Parameters - Quick Tab

Select the Quick tab of the 1-Way ANOVA: Sample Size Parameters dialog box to access options to establish the basic parameters for analyzing sample size for the one-way ANOVA.

Fixed Parameters

The entries in the boxes under Fixed Parameters establish the fixed, or baseline, parameters for subsequent power calculations and graphs. Parameters that are not varied explicitly as the dependent (X-axis) variables in a graphical analysis will be set equal to these values.

No. of Groups.

In the No.of Groups box, enter the number of independent samples on which the analysis is based.

Alpha

In the Alpha box, enter the type I error rate used in determining the critical value for the F-statistic.

Power Goal

In the Power Goal box, enter the minimum acceptable power, for which a minimum sample size is calculated. If the search for an acceptable sample size is successful, the actual power of the statistical test will be greater than or equal to this value.

RMSSE

In the RMSSE box, enter the root mean square standardized effect (RMSSE). Note that you can enter this number directly, or you can click the Calculate Effects button to have STATISTICA calculate it from cell means and contrast weights.

Type of Model

The program can handle power analysis for two distinctly different kinds of models. The more familiar model, called fixed effects, restricts you to making inferences about the actual treatments that are included in the experiment. The random effects model assumes you have randomly sampled your treatment levels from some larger population of levels.  In this case, you can make inferences about the variation in the entire population of potential treatments.

Fixed Effects

Select the Fixed Effects option button for a fixed effects model, which is by far the more common type.

Random Effects

Select the Random Effects option button for a random effects model.

Calculate Effects

Click the Calculate Effects button to display the ANOVA Effects Calculation dialog box. This dialog box provides a convenient facility for calculating measures of effect size from group means and the population standard deviation.