Computes a Fisher confidence interval for a population phi correlation.
This function requires the frequency counts from a 2 x 2 contingency table
for two dichotomous variables. This measure of association is usually most
appropriate when both dichotomous variables are naturally dichotomous.
Usage
ci.phi(alpha, f00, f01, f10, f11)
Arguments
- alpha
alpha level for 1-alpha confidence
- f00
number of participants with y = 0 and x = 0
- f01
number of participants with y = 0 and x = 1
- f10
number of participants with y = 1 and x = 0
- f11
number of participants with y = 1 and x = 1
Value
Returns a 1-row matrix. The columns are:
Estimate - estimate of phi correlation
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
References
Bishop YMM, Fienberg SE, Holland PW (1975).
Discrete Multivariate Analysis.
MIT Press.
Examples
ci.phi(.05, 229, 28, 96, 24)
#> Estimate SE LL UL
#> 0.1229976 0.05477117 0.01462398 0.2285149
# Should return:
# Estimate SE LL UL
# 0.1229976 0.05477117 0.01462398 0.2285149