power.prop.ps

Computes the approximate power of a test for equal population proportions in
a paired-samples design (the McNemar test). This function requires planning
values for both proportions and a phi coefficient that describes the
correlation between the two dichotomous measurements. The proportion planning
values can set to .5 for a conservatively low power estimate. The planning
value for the proportion difference (effect size) could be set to the
difference of the two proportion planning values or it could be set to a
minimally interesting effect size. Set the phi correlation planning value
to the smallest value within a plausible range for a conservatively low power
estimate.

Implements confidence interval and sample size methods that
are especially useful in psychological research. The methods can be
applied in 1-group, 2-group, paired-samples, and multiple-group designs
and to a variety of parameters including means, medians, proportions,
slopes, standardized mean differences, standardized linear contrasts
of means, plus several measures of correlation and association.
Confidence interval and sample size functions are given for single
parameters as well as differences, ratios, and linear contrasts of
parameters. The sample size functions can be used to approximate the
sample size needed to estimate a parameter or function of parameters
with desired confidence interval precision or to perform a variety of
hypothesis tests (directional two-sided, equivalence, superiority,
noninferiority) with desired power. For details see: Statistical Methods
for Psychologists, Volumes 1 – 4, <https://dgbonett.sites.ucsc.edu/>.

Douglas G. Bonett

statpsych

Statistical Methods for Psychologists

Robert J. Calin-Jageman

power.prop.ps function

<dl><dt>alpha</dt>
<dd>alpha level for hypothesis test</dd>
<dt>n</dt>
<dd>planned sample size</dd>
<dt>p1</dt>
<dd>planning value of proportion for measurement 1</dd>
<dt>p2</dt>
<dd>planning value of proportion for measurement 2</dd>
<dt>phi</dt>
<dd>planning value of phi correlation</dd>
<dt>es</dt>
<dd>planning value of proportion difference</dd></dl>

Arguments

Approximates the power of a paired-samples test of equal proportions for a
planned sample size — power.prop.ps

<dl>

<dt>alpha</dt>
<dd>alpha level for hypothesis test</dd>


<dt>n</dt>
<dd>planned sample size</dd>


<dt>p1</dt>
<dd>planning value of proportion for measurement 1</dd>


<dt>p2</dt>
<dd>planning value of proportion for measurement 2</dd>


<dt>phi</dt>
<dd>planning value of phi correlation</dd>


<dt>es</dt>
<dd>planning value of proportion difference</dd>

</dl>

power.prop.ps: Approximates the power of a paired-samples test of equal proportions for a planned sample size

Description

Usage

Value

Arguments

Examples