Rethinking Shapley Value for Negative Interactions in Non-convex Games

An axiom-based solution in cooperative games. -The Shapley value 𝜙 ! 𝑣 calculates the average change in the model output 𝑣(⋅) according to the participation of the target feature 𝑖. Motivation Feature Attribution & Shapley value • Theoretically, most feature attributions are grounded in the Shapley value. 3 [𝑣 𝑆 ∪ 𝑖 -𝑣 𝑆 ] • 𝑣 : game (or model output) • 𝑁 : a set of the entire players (or features) • 𝑛, 𝑠 : the size of 𝑁, 𝑆