Statistics/Testing Data/Spearmans

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Spearman Rank- Correlation coefficient

Spearman developed a method of measuring rank correlation known as spearman rank correlation coefficient. It is generally denoted by rs. There are three cases while calculating Spearman rank correlation coefficient:

Case i When ranks are given

Case ii When ranks are not given

Case iii Repeated ranks

The formula for calculating Spearman rank correlation coefficient is same for case i and ii. The formula is,


                     r_s = 1-\frac {6\sum \!\,d^2}
{n(n^2 - 1)}

Where,

n = The number of items or individuals being ranked

d = R_1 - R_2

R_1 = The rank of items with respect to first variable

R_2 = The rank of items with respect to second variable