Equality correlation method is a statistical measure showing the extent to which the random variable being measured has similarities with the reference variable, where the determination of the correlation index is done by calculating the Harmony in Gradation Index of the relationship between the random variable as measured by the reference variable. In this case, an index equal to one represents a perfect similarity between the elements of the variable as measured by the pairs of elements of the reference variable, let R be the reference variable = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11} and Y is random variable measured = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22}, then Y has an equality correlation index equal to one through the relationship function Y = 2R, since all elements of Y are equal to twice of the pairing elements of R.


  1. Fill in the size of the measured random variable (Y), which should be the same as the size of the reference variable (R)
  2. Fill in the value of each element Y and R,  make sure there is NO value of an element equal to ZERO; then click CALCULATE

Y (Variable Measured)R (Reference Variable)

Calculation Result:

The Population of the Random variable (N):
Index of the Perfect Equality Correlation: