View-based Explanations for Graph Neural Networks

Fuente: arXiv
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Autori principali: Chen, Tingyang, Qiu, Dazhuo, Wu, Yinghui, Khan, Arijit, Ke, Xiangyu, Gao, Yunjun
Natura: Preprint
Pubblicazione: 2024
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author Chen, Tingyang
Qiu, Dazhuo
Wu, Yinghui
Khan, Arijit
Ke, Xiangyu
Gao, Yunjun
author_facet Chen, Tingyang
Qiu, Dazhuo
Wu, Yinghui
Khan, Arijit
Ke, Xiangyu
Gao, Yunjun
contents Generating explanations for graph neural networks (GNNs) has been studied to understand their behavior in analytical tasks such as graph classification. Existing approaches aim to understand the overall results of GNNs rather than providing explanations for specific class labels of interest, and may return explanation structures that are hard to access, nor directly queryable.We propose GVEX, a novel paradigm that generates Graph Views for EXplanation. (1) We design a two-tier explanation structure called explanation views. An explanation view consists of a set of graph patterns and a set of induced explanation subgraphs. Given a database G of multiple graphs and a specific class label l assigned by a GNN-based classifier M, it concisely describes the fraction of G that best explains why l is assigned by M. (2) We propose quality measures and formulate an optimization problem to compute optimal explanation views for GNN explanation. We show that the problem is $Σ^2_P$-hard. (3) We present two algorithms. The first one follows an explain-and-summarize strategy that first generates high-quality explanation subgraphs which best explain GNNs in terms of feature influence maximization, and then performs a summarization step to generate patterns. We show that this strategy provides an approximation ratio of 1/2. Our second algorithm performs a single-pass to an input node stream in batches to incrementally maintain explanation views, having an anytime quality guarantee of 1/4 approximation. Using real-world benchmark data, we experimentally demonstrate the effectiveness, efficiency, and scalability of GVEX. Through case studies, we showcase the practical applications of GVEX.
format Preprint
id arxiv_https___arxiv_org_abs_2401_02086
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle View-based Explanations for Graph Neural Networks
Chen, Tingyang
Qiu, Dazhuo
Wu, Yinghui
Khan, Arijit
Ke, Xiangyu
Gao, Yunjun
Machine Learning
Databases
Generating explanations for graph neural networks (GNNs) has been studied to understand their behavior in analytical tasks such as graph classification. Existing approaches aim to understand the overall results of GNNs rather than providing explanations for specific class labels of interest, and may return explanation structures that are hard to access, nor directly queryable.We propose GVEX, a novel paradigm that generates Graph Views for EXplanation. (1) We design a two-tier explanation structure called explanation views. An explanation view consists of a set of graph patterns and a set of induced explanation subgraphs. Given a database G of multiple graphs and a specific class label l assigned by a GNN-based classifier M, it concisely describes the fraction of G that best explains why l is assigned by M. (2) We propose quality measures and formulate an optimization problem to compute optimal explanation views for GNN explanation. We show that the problem is $Σ^2_P$-hard. (3) We present two algorithms. The first one follows an explain-and-summarize strategy that first generates high-quality explanation subgraphs which best explain GNNs in terms of feature influence maximization, and then performs a summarization step to generate patterns. We show that this strategy provides an approximation ratio of 1/2. Our second algorithm performs a single-pass to an input node stream in batches to incrementally maintain explanation views, having an anytime quality guarantee of 1/4 approximation. Using real-world benchmark data, we experimentally demonstrate the effectiveness, efficiency, and scalability of GVEX. Through case studies, we showcase the practical applications of GVEX.
title View-based Explanations for Graph Neural Networks
topic Machine Learning
Databases
url https://arxiv.org/abs/2401.02086