size.test.cronbach2

Computes the sample size required to test a difference in population
Cronbach reliability coefficients with desired power in a 2-group design.

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.cronbach2 function

<dl><dt>alpha</dt>
<dd>alpha level for hypothesis test</dd>
<dt>pow</dt>
<dd>desired power</dd>
<dt>rel1</dt>
<dd>reliability planning value for group 1</dd>
<dt>rel2</dt>
<dd>reliability planning value for group 2</dd>
<dt>r</dt>
<dd>number of measurements (items, raters)</dd></dl>

Arguments

Sample size to test equality of Cronbach reliability coefficients in a
2-group design — size.test.cronbach2

<dl>

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


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


<dt>rel1</dt>
<dd>reliability planning value for group 1</dd>


<dt>rel2</dt>
<dd>reliability planning value for group 2</dd>


<dt>r</dt>
<dd>number of measurements (items, raters)</dd>

</dl>

size.test.cronbach2: Sample size to test equality of Cronbach reliability coefficients in a 2-group design

Description

Usage

Value

Arguments

References

Examples