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arXiv 2407.09381cs.LG
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基于曲率的重连的有效性与GNN中超参数的作用再探

The Effectiveness of Curvature-Based Rewiring and the Role of Hyperparameters in GNNs Revisited

Vrije Universiteit Brussel(布鲁塞尔自由大学);Harvard University(哈佛大学)

Floriano Tori, Vincent Holst, Vincent Ginis

AI总结:

本文重新评估基于曲率的重连在真实世界GNN数据集上的效果,发现所选边不符合瓶颈理论标准,SOTA准确率多为超参数扫描的异常值,而非一致性能提升。

摘要:

消息传递是图神经网络(GNNs)中的主导范式。然而,消息传递的效率可能受到图拓扑的限制。当信息在传播过程中因通过瓶颈时被过度压缩而丢失时,就会发生这种情况。为了解决这个问题,最近的研究工作集中在图重连技术上,该技术将源自数据的输入图与执行消息传递的计算图断开连接。一种突出的方法是使用离散图曲率度量(已提出多种变体)来识别瓶颈并围绕其进行重连,以促进信息传播。虽然过度压缩已在合成数据集中得到证明,但在本工作中,我们重新评估了基于曲率的重连为真实世界数据集带来的性能提升。我们表明,在这些数据集中,重连过程中选择的边与识别瓶颈的理论标准不符。这意味着它们在消息传递过程中不一定过度压缩信息。随后,我们证明这些数据集上的最先进(SOTA)准确率是来自超参数扫描的异常值——包括训练用的超参数和与重连算法相关的专用超参数——而非一致的性能提升。总之,我们的分析细化了基于曲率的重连在真实世界数据集中的有效性,并为评估GNN准确率改进的方法带来了新的视角。

英文摘要:

Message passing is the dominant paradigm in Graph Neural Networks (GNNs). The efficiency of message passing, however, can be limited by the topology of the graph. This happens when information is lost during propagation due to being oversquashed when travelling through bottlenecks. To remedy this, recent efforts have focused on graph rewiring techniques, which disconnect the input graph originating from the data and the computational graph, on which message passing is performed. A prominent approach for this is to use discrete graph curvature measures, of which several variants have been proposed, to identify and rewire around bottlenecks, facilitating information propagation. While oversquashing has been demonstrated in synthetic datasets, in this work we reevaluate the performance gains that curvature-based rewiring brings to real-world datasets. We show that in these datasets, edges selected during the rewiring process are not in line with theoretical criteria identifying bottlenecks. This implies they do not necessarily oversquash information during message passing. Subsequently, we demonstrate that SOTA accuracies on these datasets are outliers originating from sweeps of hyperparameters -- both the ones for training and dedicated ones related to the rewiring algorithm -- instead of consistent performance gains. In conclusion, our analysis nuances the effectiveness of curvature-based rewiring in real-world datasets and brings a new perspective on the methods to evaluate GNN accuracy improvements.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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