size.test.prop2

Computes the sample size in each group required to test a difference in
population proportions with desired power and a continuity correction in a
2-group design. This function requires planning values for both proportions.
Set each proportion planning value to .5 for a conservatively large sample
size requirement. This function does not use the typical sample size approach
where the effect size is assumed to equal the difference in proportion
planning values. This function does not require the planning value for the
proportion difference (effect size) to equal the difference of the two
proportion planning values; for example, the planning value of the proportion
difference could be set equal to a minimally interesting effect size.

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

size.test.prop2 function

<dl><dt>alpha</dt>
<dd>alpha level for hypothesis test</dd>
<dt>pow</dt>
<dd>desired power</dd>
<dt>p1</dt>
<dd>planning value of proportion for group 1</dd>
<dt>p2</dt>
<dd>planning value of proportion for group 2</dd>
<dt>es</dt>
<dd>planning value of proportion difference (effect size)</dd></dl>

Arguments

Sample size for a test of a 2-group proportion difference — size.test.prop2

<dl>

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


<dt>pow</dt>
<dd>desired power</dd>


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


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


<dt>es</dt>
<dd>planning value of proportion difference (effect size)</dd>

</dl>

size.test.prop2: Sample size for a test of a 2-group proportion difference

Description

Usage

Value

Arguments

Examples