Spatiotemporal Evolution Pattern and Driving Factors of Higher-Education Population in China

Table 3

Types of interactions between two factors [33].

Interaction	Description
Weaken, nonlinear	PD (X1 ∩ X2) < Min (PD (X1), PD (X2))
Weaken, unilinear	Min (PD (X1), PD (X2)) < PD (X1∩ X2) < Max (PD (X1)), PD(X2))
Enhance, bilinear	PD (X1 ∩ X2) > Max (PD (X1), PD (X2))
Independent	PD (X1 ∩ X2) = PD (X1) + PD (X2)
Enhance, nonlinear	PD (X1 ∩ X2) > PD (X1) + PD (X2)

Note: the symbol “∩” denotes the intersection between X1 and X2.