size.ci.tetra {statpsych}

Sample size for a tetrachoric correlation confidence interval

Description

Computes the sample size required to estimate a tetrachoric correlation with desired confidence interval precision. Set the tetrachoric planning value to the smallest value within a plausible range for a conservatively large sample size.

Usage

size.ci.tetra(alpha, p1, p2, cor, w)

Arguments

alpha

alpha level for 1 - alpha confidence

p1

planning value for row 1 marginal proportion

p2

planning value for column 1 marginal proportion

cor

tetrachoric planning value

w

desired confidence interval width

Value

Returns the required sample size

References

Bonett DG, Price RM (2005). “Inferential methods for the tetrachoric correlation coefficient.” Journal of Educational and Behavioral Statistics, 30(2), 213–225. ISSN 1076-9986, doi:10.3102/10769986030002213.

Examples

size.ci.tetra(.05, .4, .3, .5, .3)

# Should return:
#  Sample size
#          296