Table 3 Types of interactions between two covariates.
Criterion | Interaction |
|---|---|
q(X1 ∩ X2) < Min(q(X1), q(X2)) | Nonlinear weakening |
Min(q(X1), q(X2)) < q(X1 ∩ X2) < Max(q(X1)), q(X2)) | Single-factor nonlinear weakening |
q(X1 ∩ X2) > Max(q(X1), q(X2)) | Two-factor enhancement |
q (X1 ∩ X2) = q(X1) + q(X2) | Independence from each other |
q(X1 ∩ X2) > q(X1) + q(X2) | Nonlinear enhancement |
