Why Does AHP Use A Hierarchy?

Complex systems can best be understood by breaking them down into their constituent elements, structuring the elements hierarchically, and then composing, or synthesizing, judgments on the relative importance of the elements at each level of the hierarchy into a set of overall priorities. Hierarchies are a fundamental tool of the human mind. They involve identifying the elements of a problem, grouping the elements into homogeneous sets, and arranging these sets in different levels. The simplest hierarchies are linear, rising or descending from one level to another, such as physics hierarchies that rise from atoms to molecules to compounds and so on; the most complex are networks with interacting elements, such as systems representing the learning process of a child.