Verbal
Explanation of the Scale

If jth and ith criteria are of the same importance
s_{ij}=1
(comparing the same criteria always leads to result
s_{ii}=1 – all elements on main diagonal are equal to 1)

If ith criterion is slightly preferred to ith s_{ij}=3

If ith criterion is strongly preferred to ith s_{ij}=5

If ith criterion is massively preferred to ith s_{ij}=7

If ith criterion is absolutely preferred to ith s_{ij}=9
Intermediate stages expressed by numbers 2,4,6,8
are allowed, too.