ci.cronbach2

Computes a confidence interval for a difference in population Cronbach
reliability coefficients in a 2-group design. The number of measurements
(e.g., items or raters) used in each group need not be equal.

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

ci.cronbach2 function

<dl><dt>alpha</dt>
<dd>alpha level for 1-alpha confidence</dd>
<dt>rel1</dt>
<dd>estimated Cronbach reliability for group 1</dd>
<dt>rel2</dt>
<dd>estimated Cronbach reliability for group 2</dd>
<dt>r1</dt>
<dd>number of measurements used in group 1</dd>
<dt>r2</dt>
<dd>number of measurements used in group 2</dd>
<dt>n1</dt>
<dd>sample size for group 1</dd>
<dt>n2</dt>
<dd>sample size for group 2</dd></dl>

Arguments

Confidence interval for a difference in Cronbach reliabilities in a 2-group
design — ci.cronbach2

<dl>

<dt>alpha</dt>
<dd>alpha level for 1-alpha confidence</dd>


<dt>rel1</dt>
<dd>estimated Cronbach reliability for group 1</dd>


<dt>rel2</dt>
<dd>estimated Cronbach reliability for group 2</dd>


<dt>r1</dt>
<dd>number of measurements used in group 1</dd>


<dt>r2</dt>
<dd>number of measurements used in group 2</dd>


<dt>n1</dt>
<dd>sample size for group 1</dd>


<dt>n2</dt>
<dd>sample size for group 2</dd>

</dl>

ci.cronbach2: Confidence interval for a difference in Cronbach reliabilities in a 2-group design

Description

Usage

Value

Arguments

References

Examples