tetrachoric {exametrika}R Documentation

Tetrachoric Correlation

Description

Tetrachoric Correlation is superior to the phi coefficient as a measure of the relation of an item pair. See Divgi, 1979; Olsson, 1979;Harris, 1988.

Usage

tetrachoric(x, y)

Arguments

x

binary vector x

y

binary vector y

Value

Returns a single numeric value of class "exametrika" representing the tetrachoric correlation coefficient between the two binary variables. The value ranges from -1 to 1, where:

References

Divgi, D. R. (1979). Calculation of the tetrachoric correlation coefficient. Psychometrika, 44, 169–172.

Olsson, U. (1979). Maximum likelihood estimation of the polychoric correlation coefficient. Psychometrika,44, 443–460.

Harris, B. (1988). Tetrachoric correlation coefficient. In L. Kotz, & N. L. Johnson (Eds.), Encyclopedia of statistical sciences (Vol. 9, pp. 223–225). Wiley.


[Package exametrika version 1.5.1 Index]