The POWER Procedure |
Table 67.29 displays notation for some of the more common parameters across analyses. The Associated Syntax column shows examples of relevant analysis statement options, where applicable.
Symbol |
Description |
Associated Syntax |
---|---|---|
|
significance level |
ALPHA= |
|
total sample size |
NTOTAL=, NPAIRS= |
|
sample size in th group |
NPERGROUP=, GROUPNS= |
|
allocation weight for th group (standardized to sum to 1) |
GROUPWEIGHTS= |
|
(arithmetic) mean |
MEAN= |
|
(arithmetic) mean in th group |
GROUPMEANS=, PAIREDMEANS= |
|
(arithmetic) mean difference, or |
MEANDIFF= |
|
null mean or mean difference (arithmetic) |
NULL=, NULLDIFF= |
|
geometric mean |
MEAN= |
|
geometric mean in th group |
GROUPMEANS=, PAIREDMEANS= |
|
null mean or mean ratio (geometric) |
NULL=, NULLRATIO= |
|
standard deviation (or common standard deviation per group) |
STDDEV= |
|
standard deviation in th group |
GROUPSTDDEVS=, PAIREDSTDDEVS= |
|
standard deviation of differences |
|
|
coefficient of variation, defined as the ratio of the standard deviation to the (arithmetic) mean |
CV=, PAIREDCVS= |
|
correlation |
CORR= |
|
treatment and reference (arithmetic) means for equivalence test |
GROUPMEANS=, PAIREDMEANS= |
|
treatment and reference geometric means for equivalence test |
GROUPMEANS=, PAIREDMEANS= |
|
lower equivalence bound |
LOWER= |
|
upper equivalence bound |
UPPER= |
|
distribution with d.f. and noncentrality |
|
|
distribution with numerator d.f. , denominator d.f. , and noncentrality |
|
|
th percentile of distribution with d.f. |
|
|
th percentile of distribution with numerator d.f. and denominator d.f. |
|
|
binomial distribution with sample size and proportion |
A "lower one-sided" test is associated with SIDES=L (or SIDES=1 with the effect smaller than the null value), and an "upper one-sided" test is associated with SIDES=U (or SIDES=1 with the effect larger than the null value).
Owen (1965) defines a function, known as Owen’s , that is convenient for representing terms in power formulas for confidence intervals and equivalence tests:
where and are the density and cumulative distribution function of the standard normal distribution, respectively.
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