Relevant Walk Search for Explaining Graph Neural Networks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xiong, Ping, Schnake, Thomas, Gastegger, Michael, Montavon, Grégoire, Müller, Klaus-Robert, Nakajima, Shinichi
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918518627237888
author Xiong, Ping
Schnake, Thomas
Gastegger, Michael
Montavon, Grégoire
Müller, Klaus-Robert
Nakajima, Shinichi
author_facet Xiong, Ping
Schnake, Thomas
Gastegger, Michael
Montavon, Grégoire
Müller, Klaus-Robert
Nakajima, Shinichi
contents Graph Neural Networks (GNNs) have become important machine learning tools for graph analysis, and its explainability is crucial for safety, fairness, and robustness. Layer-wise relevance propagation for GNNs (GNN-LRP) evaluates the relevance of \emph{walks} to reveal important information flows in the network, and provides higher-order explanations, which have been shown to be superior to the lower-order, i.e., node-/edge-level, explanations. However, identifying relevant walks by GNN-LRP requires {\em exponential} computational complexity with respect to the network depth, which we will remedy in this paper. Specifically, we propose {\em polynomial-time} algorithms for finding top-$K$ relevant walks, which drastically reduces the computation and thus increases the applicability of GNN-LRP to large-scale problems. Our proposed algorithms are based on the \emph{max-product} algorithm -- a common tool for finding the maximum likelihood configurations in probabilistic graphical models -- and can find the most relevant walks exactly at the neuron level and approximately at the node level. Our experiments demonstrate the performance of our algorithms at scale and their utility across application domains, i.e., on epidemiology, molecular, and natural language benchmarks. We provide our codes under \href{https://github.com/xiong-ping/rel_walk_gnnlrp}{github.com/xiong-ping/rel\_walk\_gnnlrp}.
format Preprint
id arxiv_https___arxiv_org_abs_2605_23673
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Relevant Walk Search for Explaining Graph Neural Networks
Xiong, Ping
Schnake, Thomas
Gastegger, Michael
Montavon, Grégoire
Müller, Klaus-Robert
Nakajima, Shinichi
Machine Learning
Graph Neural Networks (GNNs) have become important machine learning tools for graph analysis, and its explainability is crucial for safety, fairness, and robustness. Layer-wise relevance propagation for GNNs (GNN-LRP) evaluates the relevance of \emph{walks} to reveal important information flows in the network, and provides higher-order explanations, which have been shown to be superior to the lower-order, i.e., node-/edge-level, explanations. However, identifying relevant walks by GNN-LRP requires {\em exponential} computational complexity with respect to the network depth, which we will remedy in this paper. Specifically, we propose {\em polynomial-time} algorithms for finding top-$K$ relevant walks, which drastically reduces the computation and thus increases the applicability of GNN-LRP to large-scale problems. Our proposed algorithms are based on the \emph{max-product} algorithm -- a common tool for finding the maximum likelihood configurations in probabilistic graphical models -- and can find the most relevant walks exactly at the neuron level and approximately at the node level. Our experiments demonstrate the performance of our algorithms at scale and their utility across application domains, i.e., on epidemiology, molecular, and natural language benchmarks. We provide our codes under \href{https://github.com/xiong-ping/rel_walk_gnnlrp}{github.com/xiong-ping/rel\_walk\_gnnlrp}.
title Relevant Walk Search for Explaining Graph Neural Networks
topic Machine Learning
url https://arxiv.org/abs/2605.23673