A critical look at the evaluation of GNNs under heterophily: Are we really making progress?

Fuente: arXiv
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Main Authors: Platonov, Oleg, Kuznedelev, Denis, Diskin, Michael, Babenko, Artem, Prokhorenkova, Liudmila
Format: Preprint
Published: 2023
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author Platonov, Oleg
Kuznedelev, Denis
Diskin, Michael
Babenko, Artem
Prokhorenkova, Liudmila
author_facet Platonov, Oleg
Kuznedelev, Denis
Diskin, Michael
Babenko, Artem
Prokhorenkova, Liudmila
contents Node classification is a classical graph machine learning task on which Graph Neural Networks (GNNs) have recently achieved strong results. However, it is often believed that standard GNNs only work well for homophilous graphs, i.e., graphs where edges tend to connect nodes of the same class. Graphs without this property are called heterophilous, and it is typically assumed that specialized methods are required to achieve strong performance on such graphs. In this work, we challenge this assumption. First, we show that the standard datasets used for evaluating heterophily-specific models have serious drawbacks, making results obtained by using them unreliable. The most significant of these drawbacks is the presence of a large number of duplicate nodes in the datasets Squirrel and Chameleon, which leads to train-test data leakage. We show that removing duplicate nodes strongly affects GNN performance on these datasets. Then, we propose a set of heterophilous graphs of varying properties that we believe can serve as a better benchmark for evaluating the performance of GNNs under heterophily. We show that standard GNNs achieve strong results on these heterophilous graphs, almost always outperforming specialized models. Our datasets and the code for reproducing our experiments are available at https://github.com/yandex-research/heterophilous-graphs
format Preprint
id arxiv_https___arxiv_org_abs_2302_11640
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A critical look at the evaluation of GNNs under heterophily: Are we really making progress?
Platonov, Oleg
Kuznedelev, Denis
Diskin, Michael
Babenko, Artem
Prokhorenkova, Liudmila
Machine Learning
Node classification is a classical graph machine learning task on which Graph Neural Networks (GNNs) have recently achieved strong results. However, it is often believed that standard GNNs only work well for homophilous graphs, i.e., graphs where edges tend to connect nodes of the same class. Graphs without this property are called heterophilous, and it is typically assumed that specialized methods are required to achieve strong performance on such graphs. In this work, we challenge this assumption. First, we show that the standard datasets used for evaluating heterophily-specific models have serious drawbacks, making results obtained by using them unreliable. The most significant of these drawbacks is the presence of a large number of duplicate nodes in the datasets Squirrel and Chameleon, which leads to train-test data leakage. We show that removing duplicate nodes strongly affects GNN performance on these datasets. Then, we propose a set of heterophilous graphs of varying properties that we believe can serve as a better benchmark for evaluating the performance of GNNs under heterophily. We show that standard GNNs achieve strong results on these heterophilous graphs, almost always outperforming specialized models. Our datasets and the code for reproducing our experiments are available at https://github.com/yandex-research/heterophilous-graphs
title A critical look at the evaluation of GNNs under heterophily: Are we really making progress?
topic Machine Learning
url https://arxiv.org/abs/2302.11640