Correlation, Pearson

The Pearson correlation coefficient (also known as Pearson product-moment correlation coefficient) r is a measure to determine the relationship (instead of difference) between two quantitative variables (interval/ratio) and the degree to which the two variables coincide with one another—that is, the extent to which two variables are linearly related: changes in one variable correspond to changes in another variable. In fact, a variety of different correlation coefficients (such as phi correlation coefficient, point-biserial correlation, Spearman’s rho, partial correlation, and part correlation) have been developed over the years for measuring relationships between sets of data, and the Pearson correlation coefficient (also referred to Pearson’s r) is the most common measure of correlation and has been widely used in the sciences as a measure of ...