Coefficient of Correlation Denoted

There are two methods which measure the degree of correlation among two variables these are denoted by R and r.

(a) Coefficient of correlation denoted by r, this gives a measure of the strength of association among two variables one the dependent variable the other the independent variable r can range between -1 and +1 for perfect positive correlation and perfect negative correlation respectively along with zero indicating no relation that is for perfect positive correlation y increase linearly along with x increment.

(b) Rank correlation coefficient denoted by R is utilized to measure association among two sets of ranked or ordered data.  R can also vary from +1, perfect positive rank correlation and -1 perfect negative rank correlation whereas O or any type of number near zero representing no correlation.