GnnXemplar: Exemplars to Explanations -- Natural Language Rules for Global GNN Interpretability

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Armgaan, Burouj, Jain, Eshan, Pandey, Harsh, Chandran, Mahesh, Ranu, Sayan
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866911238750994432
author Armgaan, Burouj
Jain, Eshan
Pandey, Harsh
Chandran, Mahesh
Ranu, Sayan
author_facet Armgaan, Burouj
Jain, Eshan
Pandey, Harsh
Chandran, Mahesh
Ranu, Sayan
contents Graph Neural Networks (GNNs) are widely used for node classification, yet their opaque decision-making limits trust and adoption. While local explanations offer insights into individual predictions, global explanation methods, those that characterize an entire class, remain underdeveloped. Existing global explainers rely on motif discovery in small graphs, an approach that breaks down in large, real-world settings where subgraph repetition is rare, node attributes are high-dimensional, and predictions arise from complex structure-attribute interactions. We propose GnnXemplar, a novel global explainer inspired from Exemplar Theory from cognitive science. GnnXemplar identifies representative nodes in the GNN embedding space, exemplars, and explains predictions using natural language rules derived from their neighborhoods. Exemplar selection is framed as a coverage maximization problem over reverse k-nearest neighbors, for which we provide an efficient greedy approximation. To derive interpretable rules, we employ a self-refining prompt strategy using large language models (LLMs). Experiments across diverse benchmarks show that GnnXemplar significantly outperforms existing methods in fidelity, scalability, and human interpretability, as validated by a user study with 60 participants.
format Preprint
id arxiv_https___arxiv_org_abs_2509_18376
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle GnnXemplar: Exemplars to Explanations -- Natural Language Rules for Global GNN Interpretability
Armgaan, Burouj
Jain, Eshan
Pandey, Harsh
Chandran, Mahesh
Ranu, Sayan
Machine Learning
Social and Information Networks
Graph Neural Networks (GNNs) are widely used for node classification, yet their opaque decision-making limits trust and adoption. While local explanations offer insights into individual predictions, global explanation methods, those that characterize an entire class, remain underdeveloped. Existing global explainers rely on motif discovery in small graphs, an approach that breaks down in large, real-world settings where subgraph repetition is rare, node attributes are high-dimensional, and predictions arise from complex structure-attribute interactions. We propose GnnXemplar, a novel global explainer inspired from Exemplar Theory from cognitive science. GnnXemplar identifies representative nodes in the GNN embedding space, exemplars, and explains predictions using natural language rules derived from their neighborhoods. Exemplar selection is framed as a coverage maximization problem over reverse k-nearest neighbors, for which we provide an efficient greedy approximation. To derive interpretable rules, we employ a self-refining prompt strategy using large language models (LLMs). Experiments across diverse benchmarks show that GnnXemplar significantly outperforms existing methods in fidelity, scalability, and human interpretability, as validated by a user study with 60 participants.
title GnnXemplar: Exemplars to Explanations -- Natural Language Rules for Global GNN Interpretability
topic Machine Learning
Social and Information Networks
url https://arxiv.org/abs/2509.18376