Table 1.

Saaty’s pairwise comparison scale

Intensity of importance	Degree of preference	Description
1	Equal importance	Two activities contribute equally to the objective.
2	Weak
3	Moderate importance	Experience and judgment slightly to moderately favour one activity over another.
4	Moderate plus
5	Strong importance	Experience and judgment strongly or essentially favour one activity over another.
6	Strong plus
7	Very strong or demonstrated importance	An activity is strongly favoured over another and its dominance is showed in practice.
8	Very, very strong
9	Extreme importance	The evidence of favouring one activity over another is of the highest degree possible of an affirmation.
Reciprocals of above values	If activity i has one of the above non-zero number assigned to it when compared to with activity j, then j has the reciprocal value when compared with i	Reasonable assumption.
1.1–1.9	If the activities are very close	May be difficult to assign the best value but when compared with other contrasting activities, the size of the small numbers would not be too noticeable, yet they can still indicate the relative importance of the activities.