The POWER Procedure
- Overview
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Getting Started
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Syntax
PROC POWER Statement LOGISTIC Statement MULTREG Statement ONECORR Statement ONESAMPLEFREQ Statement ONESAMPLEMEANS Statement ONEWAYANOVA Statement PAIREDFREQ Statement PAIREDMEANS Statement PLOT Statement TWOSAMPLEFREQ Statement TWOSAMPLEMEANS Statement TWOSAMPLESURVIVAL Statement TWOSAMPLEWILCOXON Statement
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Details
Overview of Power Concepts Summary of Analyses Specifying Value Lists in Analysis Statements Sample Size Adjustment Options Error and Information Output Displayed Output ODS Table Names Computational Resources Computational Methods and Formulas ODS Graphics ODS Styles Suitable for Use with PROC POWER
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Examples
One-Way ANOVA The Sawtooth Power Function in Proportion Analyses Simple AB/BA Crossover Designs Noninferiority Test with Lognormal Data Multiple Regression and Correlation Comparing Two Survival Curves Confidence Interval Precision Customizing Plots Binary Logistic Regression with Independent Predictors Wilcoxon-Mann-Whitney Test
- References
| Displayed Output |
If you use the PLOTONLY option in the PROC POWER statement, the procedure displays only graphical output. Otherwise, the displayed output of the POWER procedure includes the following:
the "Fixed Scenario Elements" table, which shows all applicable single-valued analysis parameters, in the following order: distribution, method, parameters input explicitly, and parameters supplied with defaults
an output table showing the following when applicable (in order): the index of the scenario, all multivalued input, ancillary results, the primary computed result, and error descriptions
plots (if requested)
For each input parameter, the order of the input values is preserved in the output.
Ancillary results include the following:
Actual Power, the achieved power, if it differs from the input (Nominal) power value
Actual Prob(Width), the achieved precision probability, if it differs from the input (Nominal) probability value
Actual Alpha, the achieved significance level, if it differs from the input (Nominal) alpha value
fractional sample size, if the NFRACTIONAL option is used in the analysis statement
If sample size is the result parameter and the NFRACTIONAL option is used in the analysis statement, then both "Fractional" and "Ceiling" sample size results are displayed. Fractional sample sizes correspond to the "Nominal" values of power or precision probability. Ceiling sample sizes are simply the fractional sample sizes rounded up to the nearest integer; they correspond to "Actual" values of power or precision probability.