ci.tetra {statpsych} | R Documentation |
Computes a confidence interval for an approximation to the tetrachoric correlation. This function requires the frequency counts from a 2 x 2 contingency table for two dichotomous variables. This measure of association assumes both of the dichotomous variables are artificially dichotomous.
ci.tetra(alpha, f00, f01, f10, f11)
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 |
Returns a 1-row matrix. The columns are:
Estimate - estimate of tetrachoric approximation
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
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.
ci.tetra(.05, 46, 15, 54, 85) # Should return: # Estimate LL UL # [1,] 0.5135167 0.3102345 0.6748546