Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning

Graph Neural Networks (GNNs) have demonstrated remarkable performance in tasks involving graph-structured data, but they also exhibit biases linked to node degrees. This paper explores a specific manifestation of such bias, termed Exploration Degree Bias (EDB), in the context of Reinforcement Learni...

Full description

Saved in:
Bibliographic Details
Main Authors: Peter Tarabek, David Matis
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10838508/
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832592928830128128
author Peter Tarabek
David Matis
author_facet Peter Tarabek
David Matis
author_sort Peter Tarabek
collection DOAJ
description Graph Neural Networks (GNNs) have demonstrated remarkable performance in tasks involving graph-structured data, but they also exhibit biases linked to node degrees. This paper explores a specific manifestation of such bias, termed Exploration Degree Bias (EDB), in the context of Reinforcement Learning (RL). We show that EDB arises from the inherent design of GNNs, where nodes with high or low degrees disproportionately influence output logits used for decision-making. This phenomenon impacts exploration in RL, skewing it away from mid-degree nodes, potentially hindering the discovery of optimal policies. We provide a systematic investigation of EDB across widely used GNN architectures—GCN, GraphSAGE, GAT, and GIN—by quantifying correlations between node degrees and logits. Our findings reveal that EDB varies by architecture and graph configuration, with GCN and GIN exhibiting the strongest biases. Moreover, analysis of DQN and PPO RL agents illustrates how EDB can distort exploration patterns, with DQN exhibiting EDB under low exploration rates and PPO showing a partial ability to counteract these effects through its probabilistic sampling mechanism. Our contributions include defining and quantifying EDB, providing experimental insights into its existence and variability, and analyzing its implications for RL. These findings underscore the need to address degree-related biases in GNNs to enhance RL performance on graph-based tasks.
format Article
id doaj-art-66dd5a03c2904cb68e3b90679df6ebf8
institution Kabale University
issn 2169-3536
language English
publishDate 2025-01-01
publisher IEEE
record_format Article
series IEEE Access
spelling doaj-art-66dd5a03c2904cb68e3b90679df6ebf82025-01-21T00:01:03ZengIEEEIEEE Access2169-35362025-01-0113107461075710.1109/ACCESS.2025.352887810838508Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement LearningPeter Tarabek0https://orcid.org/0000-0002-4815-3933David Matis1https://orcid.org/0009-0007-9023-5725Faculty of Management Science and Informatics, University of Žilina, Žilina, SlovakiaFaculty of Management Science and Informatics, University of Žilina, Žilina, SlovakiaGraph Neural Networks (GNNs) have demonstrated remarkable performance in tasks involving graph-structured data, but they also exhibit biases linked to node degrees. This paper explores a specific manifestation of such bias, termed Exploration Degree Bias (EDB), in the context of Reinforcement Learning (RL). We show that EDB arises from the inherent design of GNNs, where nodes with high or low degrees disproportionately influence output logits used for decision-making. This phenomenon impacts exploration in RL, skewing it away from mid-degree nodes, potentially hindering the discovery of optimal policies. We provide a systematic investigation of EDB across widely used GNN architectures—GCN, GraphSAGE, GAT, and GIN—by quantifying correlations between node degrees and logits. Our findings reveal that EDB varies by architecture and graph configuration, with GCN and GIN exhibiting the strongest biases. Moreover, analysis of DQN and PPO RL agents illustrates how EDB can distort exploration patterns, with DQN exhibiting EDB under low exploration rates and PPO showing a partial ability to counteract these effects through its probabilistic sampling mechanism. Our contributions include defining and quantifying EDB, providing experimental insights into its existence and variability, and analyzing its implications for RL. These findings underscore the need to address degree-related biases in GNNs to enhance RL performance on graph-based tasks.https://ieeexplore.ieee.org/document/10838508/Exploration degree biasgraph neural networksmessage-passing mechanismnode degree biasreinforcement learning
spellingShingle Peter Tarabek
David Matis
Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
IEEE Access
Exploration degree bias
graph neural networks
message-passing mechanism
node degree bias
reinforcement learning
title Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
title_full Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
title_fullStr Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
title_full_unstemmed Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
title_short Exploration Degree Bias: The Hidden Influence of Node Degree in Graph Neural Network-Based Reinforcement Learning
title_sort exploration degree bias the hidden influence of node degree in graph neural network based reinforcement learning
topic Exploration degree bias
graph neural networks
message-passing mechanism
node degree bias
reinforcement learning
url https://ieeexplore.ieee.org/document/10838508/
work_keys_str_mv AT petertarabek explorationdegreebiasthehiddeninfluenceofnodedegreeingraphneuralnetworkbasedreinforcementlearning
AT davidmatis explorationdegreebiasthehiddeninfluenceofnodedegreeingraphneuralnetworkbasedreinforcementlearning