Sample size for biserial-phi correlation confidence interval
Source:R/statpsych3.R
size.ci.biphi.Rd
Computes the sample size required to estimate a biserial-phi correlation with desired confidence interval precision. Set the biserial-phi planning value to the smallest absolute value within a plausible range for a conservatively large sample size. The column variable is assumed to be naturally dichotomous and the row variable is assumed to be artificially dichotomous.