pi.cor

Computes approximate one-sided or two-sided prediction limits for the
estimated Pearson correlation in a future study with a planned sample
size of n. The prediction interval uses a correlation estimate from a
prior study that had a sample size of n0.
Several confidence interval sample size functions in this package require
a planning value of the expected sample value of a Pearson correlation
in the planned study. A one-sided lower correlation prediction limit is
useful as a correlation planning value for a conservatively large sample
size required to obtain a confidence interval with desired width. This
strategy for specifying a correlation planning value is useful in
applications where the population correlation in the prior study is
assumed to be very similar to the population correlation in the planned
study.
For more details, see Section 1.26 of Bonett (2021, Volume 2)

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

pi.cor function

<dl><dt>alpha</dt>
<dd>alpha value for 1-alpha confidence</dd>
<dt>cor</dt>
<dd>estimated Pearson correlation from prior study</dd>
<dt>n0</dt>
<dd>sample size used to estimate the correlation in prior study</dd>
<dt>n</dt>
<dd>planned sample size of future study</dd>
<dt>type</dt>
<dd><ul>
<li>set to 1 for two-sided prediction interval</li>
<li>set to 2 for one-sided upper prediction limit</li>
<li>set to 3 for one-sided lower prediction limit</li>
</ul></dd></dl>

Arguments

Prediction limits for a sample correlation in a future study — pi.cor

<dl>

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


<dt>cor</dt>
<dd>estimated Pearson correlation from prior study</dd>


<dt>n0</dt>
<dd>sample size used to estimate the correlation in prior study</dd>


<dt>n</dt>
<dd>planned sample size of future study</dd>


<dt>type</dt>
<dd><ul>
<li>set to 1 for two-sided prediction interval</li>
<li>set to 2 for one-sided upper prediction limit</li>
<li>set to 3 for one-sided lower prediction limit</li>
</ul></dd>

</dl>

pi.cor: Prediction limits for a sample correlation in a future study

Description

Usage

Value

Arguments

References

Examples