size.ci.second

Computes the second-stage sample size required to obtain desired confidence
interval precision. This function can use either the total sample size for
all groups in the first stage sample or a single group sample size in the
first stage sample. If the total first-stage sample size is given, then the
function computes the total sample size required in the second-stage sample.
If a single group first-stage sample size is given, then the function
computes the single-group sample size required in the second-stage sample.
The second-stage sample is combined with the first-stage sample to obtain
the desired confidence interval width.
For more details, see Section 1.30 of Bonett (2021, Volume 1)

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.ci.second function

<dl><dt>n0</dt>
<dd>first-stage sample size</dd>
<dt>w0</dt>
<dd>confidence interval width in first-stage sample</dd>
<dt>w</dt>
<dd>desired confidence interval width</dd></dl>

Arguments

Sample size for a second-stage confidence interval — size.ci.second

<dl>

<dt>n0</dt>
<dd>first-stage sample size</dd>


<dt>w0</dt>
<dd>confidence interval width in first-stage sample</dd>


<dt>w</dt>
<dd>desired confidence interval width</dd>

</dl>

size.ci.second: Sample size for a second-stage confidence interval

Description

Usage

Value

Arguments

References

Examples