The GLMPOWER Procedure

If you use the PLOTONLY option in the PROC GLMPOWER statement, the procedure displays only graphical output. Otherwise, the displayed output of the GLMPOWER procedure includes the following:

• the "Fixed Scenario Elements" table, which shows all applicable single-valued analysis parameters, in the following order: the dependent variable representing the cell means, the source of the test, the weight variable, parameters input explicitly, parameters supplied with defaults, and ancillary results

• an output table showing the following when applicable (in order): the index of the scenario, the dependent variable representing the cell means, the type of the test, the source of the test, all multivalued input, ancillary results, the primary computed result, and error descriptions

• plots (if requested)

The exception to these ordering conventions is that the DEPENDENT and EFFECTS options may be used along with the OUTPUTORDER=SYNTAX or OUTPUTORDER=REVERSE option in the POWER statement to specify the relative location of the output for dependent variable and type and source of test.

Ancillary results include the following:

• Actual Power, the achieved power, if it differs from the input (Nominal) power value

• fractional sample size, if the NFRACTIONAL option is used in the POWER statement

If sample size is the result parameter and the NFRACTIONAL option is used in the POWER statement, then both "Fractional" and "Ceiling" sample size results are displayed. Fractional sample sizes correspond to the "Nominal" values of power. Ceiling sample sizes are simply the fractional sample sizes rounded up to the nearest integer; they correspond to "Actual" values of power.

The noncentrality parameter is computed and stored in a hidden column called Noncentrality in the "Output" table.