Put the two sets of data into the seven columns
on the separate sheet.
Subtract column 5 from column 3 to complete
column 6 – the
difference between the rank orders.
Square the difference
of each – column 7 D2 – this
gets rid of the minus!
Add all the numbers in the D2 column
to give the sum of D2
Next put your final answer into this
formula.
R = the correlation coefficient D2 = sum of the square of
the differences in rank order N = the number of data used
(i.e. the number of sample points) N3 = 10 x 10 x 10
= 1000
EXAMPLE - assume
the answer for D2 = 62
R
=
1
-
6 x (total of D2)
N3 - N
R
=
1
-
6 x 62
990
R
=
1
-
372
990
R
=
1
-
0.38
R
=
0.62
Answer = 0.62
The result of Spearman’s rank may be
anywhere between + 1 and -1. The closer the answer is to
+1, the more positive is your correlation
or link. In this example, there is a 62% correlation between
the two sets of data and this shows the original hypothesis to have
been
correct.