Table 7. AHP – fundamental scale (Saaty, 1987: 165)

Intensity of importance on an absolute scale Definition Explanation
1 Equal importance Two activities contribute equally to the objective
3 Moderate importance of one over another Experience and judgement strongly favor one activity over another
5 Essential or strong importance Experience and judgement strongly favor one activity over another
7 Very strong importance An activity is strongly favored and its dominance demonstrated in practice
9 Extreme importance The evidence favoring one activity over another is of the highest possible order of affirmation
2, 4, 6, 8 Intermediate values between the two adjacent judgements When compromise is needed
Reciprocals If activity $i$ has one of the above numbers assigned to it when compared with activity $j$, then $j$ has the reciprocal value when compared with $i$
Rationales Ratios arising from the scale If consistency were to be forced by obtaining $n$ numerical values to span the matrix