size.ci.phi {statpsych} | R Documentation |
Sample size for phi correlation confidence interval
Description
Computes the sample size required to estimate a phi correlation with desired confidence interval precision. Set the phi correlation planning value to the smallest absolute value within a plausible range for a conservatively large sample size.
Usage
size.ci.phi(alpha, p1, p2, phi, 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 |
phi |
planning value for phi correlation |
w |
desired confidence interval width |
Value
Returns the required sample size
Examples
size.ci.phi(.05, .7, .8, .35, .2)
# Should return:
# Sample size
# 416
[Package statpsych version 1.8.0 Index]