Appendix

Based on the definition of non-additive statistical interaction (Def. SCD uses an expectation over an activation decomposition, which does not guarantee admission ofReLU(x1 +x3 +1) for I1 and ReLU(x2) for I2 through their respective decompositions. In the ideal case SCD becomes CD, which still does not satisfy Set Attributionfromabove. IH always assigns a zero attribution toI2 from hessian computations. A factorial design isan experiment that includes observations at all combinations of categories ofeachfactororfeature. In the early20th century, Fisher et al. (1926) [17] emphasized the importance of factorial designs as being the only way to obtain information about feature interactions.