Table 2.

Marking criteria of each level of the goal tree.

Comparison score	Relative importance	Description
1	Equally important	Both contribute equally to the goal
3	Slightly important	From experience, one indicator is slightly more favourable than the other
5	More important	From experience, one indicator is more favourable than the other
7	Very important	One indicator is more favourable than the other and has been proven in practice
9	Absolutely important	Significant degree of importance
(2, 4, 6, 8)	The median value of two adjacent degrees	Use when a compromise is required