Correlation Coefficient According to Data Classification

Abstract

The purpose of this writing is to introduce researcher to correlation coefficient calculation. The Pearson Product Moment Correlation Coefficient is the most common type of correlation; however, the Pearson correlation coefficient may not be applicable in all cases. There are many types of correlation coefficient. The correct choice of correlation coefficient depends on the classification of the independent variable (X) and dependent variable (Y). Data are classified into one of three types: quantitative, nominal and ordinal. This writing explains various types of correlations on the basis of X-by-Y data type combination.

Keywords: Biserial correlation coefficient, Goodman-Kruskal lambda, Pearson correlation coefficient, point biserial correlation coefficient, polychoric coerrelation coefficient, rank biserial correlation coefficient, Spearman rho, and tetrachoric correlation coefficient.

JEL Classification: C10, C12, C13, C19