size.test.prop2

Computes the sample size in each group required to test a difference in
population proportions with desired power (using 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 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.
For more details, see Section 2.23 of Bonett (2021, Volume 3)

Implements confidence interval and sample size methods that are especially
useful in psychological research but are also useful in educational, social science,
business, and biological research. This package includes more than 100 confidence
interval functions and more than 80 sample size functions for 1-group, 2-group,
paired-samples, and multiple-group designs and for a variety of parameters including
means, medians, proportions, slopes, standardized mean differences, standardized
linear contrasts of means, and several measures of correlation and association. 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 about these methods 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

References

Examples