ci.biphi: Confidence interval for a biserial-phi correlation
Description
Computes a confidence interval for a population biserial-phi correlation
using a transformation of a confidence interval for an odds ratio with .5
added to each cell frequency. This measure of association assumes the group
variable is naturally dichotomous and the response variable is artificially
dichotomous.
Usage
ci.biphi(alpha, f1, f2, n1, n2)
Value
Returns a 1-row matrix. The columns are:
Estimate - estimate of biserial-phi correlation
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
Arguments
alpha
alpha level for 1-alpha confidence
f1
number of participants in group 1 who have the attribute
f2
number of participants in group 2 who have the attribute