size.ci.sd

Computes the sample size required to estimate a population standard
deviation with desired confidence interval precision. This function
assumes that the traditional confidence interval for a population
standard deviation will be used. The traditional confidence interval
assumes that the response variable has an approximate normal
distribution and can be highly inaccurate when this assumption is not
satisfied.

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.sd function

<dl><dt>alpha</dt>
<dd>alpha level for 1-alpha confidence</dd>
<dt>r</dt>
<dd>desired upper to lower confidence interval endpoint ratio</dd></dl>

Arguments

Sample size for a standard deviation confidence interval — size.ci.sd

<dl>

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


<dt>r</dt>
<dd>desired upper to lower confidence interval endpoint ratio</dd>

</dl>

size.ci.sd: Sample size for a standard deviation confidence interval

Description

Usage

Value

Arguments

Examples