Power Analysis: Precision

The Precision dialog is available for every Power Analysis procedure (except for Univariate Linear Regression), and provides options for estimating the sample size based on specified confidence interval half-widths. The dialog is available when Single power value or Grid power values are specified for the Sample size estimate and when the Test Direction setting is set to Nondirectional (two-sided analysis).
Note: The Test Direction setting does not apply to One-Way ANOVA.

when the Estimate sample size and Grid power values options are selected (click the Grid control to display the dialog).

Confidence Interval Type(s)
Select the appropriate confidence intervals types and whether continuity correction is applied.
Note: Confidence Interval Type(s) are available only for the Power Analysis proportion procedures (One-Sample Proportion, Related-Samples Binomial Test, and Independent-Samples Binomial Test).
Specify the half-width of confidence interval
Estimates the sample size based on the confidence interval half-width value. Enter a value in the range 0 - 1. For the One-Sample Binomial test, the value must be in the range 0 - 0.5.
Note: Duplicate values are ignored.
  • Click Add to add the specified half-width value to the list.
  • Highlight an existing half-width value and click Change to update the value.
  • Highlight an existing half-width value and click Remove to remove the value from the list.