When data is organized in the form of a contingency table where the two categorical independent variables (corresponding to the row and columns) are ordered, then we can calculate a polychoric correlation coefficient. This coefficient is an approximation to what the Pearson’s correlation coefficient would be if we had continuous data. For a 2 × 2 contingency table, the polychoric correlation coefficient is called the tetrachoric correlation coefficient.
Topics
- Basic Concepts
- Calculations using Solver
- Estimates of tetrachoric correlation
- Real Statistics support
References
Uebersax, J. S. (2015) Introduction to the tetrachoric and polychoric correlation coefficients
No longer available online
Mahler, C.M. (2016) The tetrachoric correlation coefficient
https://eigenblogger.com/tag/tetrachoric-correlation-coefficient/
STATA (2017) Tetrachoric correlations for binary variables
www.stata.com/manuals13/rtetrachoric.pdf