[edit]
DALE: Differential Accumulated Local Effects for efficient and accurate global explanations
Proceedings of The 14th Asian Conference on Machine
Learning, PMLR 189:375-390, 2023.
Abstract
Accumulated Local Effect (ALE) is a method for
accurately estimating feature effects, overcoming
fundamental failure modes of previously-existed
methods, such as Partial Dependence Plots. However,
\textit{ALE’s approximation}, i.e. the method for
estimating ALE from the limited samples of the
training set, faces two weaknesses. First, it does
not scale well in cases where the input has high
dimensionality, and, second, it is vulnerable to
out-of-distribution (OOD) sampling when the training
set is relatively small. In this paper, we propose a
novel ALE approximation, called Differential
Accumulated Local Effects (DALE), which can be used
in cases where the ML model is differentiable and an
auto-differentiable framework is accessible. Our
proposal has significant computational advantages,
making feature effect estimation applicable to
high-dimensional Machine Learning scenarios with
near-zero computational overhead. Furthermore, DALE
does not create artificial points for calculating
the feature effect, resolving misleading estimations
due to OOD sampling. Finally, we formally prove
that, under some hypotheses, DALE is an unbiased
estimator of ALE and we present a method for
quantifying the standard error of the
explanation. Experiments using both synthetic and
real datasets demonstrate the value of the proposed
approach.