Rethinking Graph Regularization for Graph Neural Networks
Abstract
The graph Laplacian regularization term is usually used in semi-supervised representation learning to provide graph structure information for a model $f(X)$. However, with the recent popularity of graph neural networks (GNNs), directly encoding graph structure $A$ into a model, i.e., $f(A, X)$, has become the more common approach. While we show that graph Laplacian regularization brings little-to-no benefit to existing GNNs, and propose a simple but non-trivial variant of graph Laplacian regularization, called Propagation-regularization (P-reg), to boost the performance of existing GNN models. We provide formal analyses to show that P-reg not only infuses extra information (that is not captured by the traditional graph Laplacian regularization) into GNNs, but also has the capacity equivalent to an infinite-depth graph convolutional network. We demonstrate that P-reg can effectively boost the performance of existing GNN models on both node-level and graph-level tasks across many different datasets.
Benchmark Results
Tested on 5 datasets 12 baseline values reported too low
Tables show presented results in global context (best 3 papers + GCN + MLP).
Classic
| # | Model | Accuracy ↑ | Paper |
|---|---|---|---|
| 1 | GraphSAGE+CNA | 0.9418
±0.0033 | |
| 2 | GCN+CNA | 0.9366
±0.0048 | |
| 3 | TransformerConv | 0.9350
±0.0058 | |
| 21 | GCN | 0.9004 best reported | best at pub: SplineCNN: Fast Geometric Deep Learning with Continuous B-Spline Kernels (2017) best today: Understanding Heterophily for Graph Neural Networks (ICML 2024) |
| 39 | SAGE | 0.8911
±0.0012 | |
| 44 | GAT | 0.8897
±0.0014 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) |
| 108 | APPNP | 0.8787 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) best today: Feature Transportation Improves Graph Neural Networks (AAAI 2023) |
| 307 | GraphMix | 0.8394
±0.0057 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) Difference within reported uncertainty; not counted as underperformance. |
| 312 | GAT+P-reg | 0.8389
±0.0031 | This paper |
| 323 | DeepAPPNP | 0.8378
±0.0033 | This paper |
| 327 | GMNN | 0.8370 best reported | best at pub: Graph Convolutional Neural Networks with Node Transition Probability-based Message Passing and DropNode Regularization (2020) Difference within reported uncertainty; not counted as underperformance. |
| 342 | BVAT | 0.8360
±0.0050 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) best today: Metropolis-Hastings Data Augmentation for Graph Neural Networks (NeurIPS 2022) Difference within reported uncertainty; not counted as underperformance. |
| 389 | GCN+P-reg | 0.8338
±0.0086 | This paper |
| 466 | GraphAT | 0.8250 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) Difference within reported uncertainty; not counted as underperformance. |
| 501 | GAM | 0.8228
±0.0048 | This paper |
| 583 | Graph U-Nets | 0.8131
±0.0147 | This paper |
| 724 | MLP | 0.7768 |
| # | Model | Accuracy ↑ | Paper |
|---|---|---|---|
| 1 | CNA | 0.9575
±0.0058 | |
| 2 | IS-GIB | 0.9390
±0.0187 | |
| 3 | EERM | 0.9112
±0.0145 | |
| 20 | APPNP | 0.8142
±0.0026 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) best today: Feature Expansion for Graph Neural Networks (ICML 2023) |
| 35 | GAT | 0.8080
±0.0026 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) best today: Feature Expansion for Graph Neural Networks (ICML 2023) |
| 44 | GCN | 0.8033
±0.0088 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) |
| 61 | GraphSAGE | 0.7923
±0.0053 | |
| 185 | GCN+P-reg | 0.7483
±0.0017 | This paper |
| 191 | GraphMix | 0.7470
±0.0059 best reported | best today: Metropolis-Hastings Data Augmentation for Graph Neural Networks (NeurIPS 2022) Difference within reported uncertainty; not counted as underperformance. |
| 230 | BVAT | 0.7400
±0.0060 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) Difference within reported uncertainty; not counted as underperformance. |
| 279 | GraphAT | 0.7349
±0.0038 | prev best: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) Improvement within reported uncertainty; not highlighted. |
| 339 | GMNN | 0.7290 best reported | best at pub: Graph Convolutional Neural Networks with Node Transition Probability-based Message Passing and DropNode Regularization (2020) Difference within reported uncertainty; not counted as underperformance. |
| 350 | MLP | 0.7289
±0.0010 | |
| 352 | GAT+P-reg | 0.7286
±0.0065 | This paper |
| 361 | GAM | 0.7274
±0.0062 | This paper |
| 526 | DeepAPPNP | 0.7137
±0.0066 | This paper |
| 696 | Graph U-Nets | 0.6774
±0.0148 | This paper |
| # | Model | Accuracy ↑ | Paper |
|---|---|---|---|
| 1 | LGTL | 0.9518
±0.0011 | |
| 2 | MixHop (LO) | 0.9513
±0.0038 | |
| 3 | GraphSAGE (LO) | 0.9511
±0.0036 | |
| 17 | APPNP | 0.9355
±0.0060 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) |
| 18 | GCN | 0.9296
±0.0015 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) |
| 20 | GAT | 0.9233
±0.0018 best reported | best at pub: Tackling Over-Smoothing for General Graph Convolutional Networks (2020) |
| 116 | SAGE | 0.8881
±0.0015 | |
| 210 | MLP | 0.8690
±0.0074 | |
| 340 | GMNN | 0.8163
±0.0036 | prev best: When Does Self-Supervision Help Graph Convolutional Networks? (ICML 2020) Improvement within reported uncertainty; not highlighted. |
| 367 | GraphMix | 0.8110
±0.0078 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) Difference within reported uncertainty; not counted as underperformance. |
| 439 | GCN+P-reg | 0.8011
±0.0045 | This paper |
| 462 | BVAT | 0.7990
±0.0040 best reported | best at pub: GraphMix: Improved Training of GNNs for Semi-Supervised Learning (2019) |
| 481 | DeepAPPNP | 0.7973
±0.0022 | This paper |
| 497 | GAM | 0.7960
±0.0063 | This paper |
| 581 | GraphAT | 0.7910
±0.0020 | This paper |
| 652 | GAT+P-reg | 0.7839
±0.0027 | This paper |
| 699 | Graph U-Nets | 0.7776
±0.0084 | This paper |
OGB
| # | Model | ROC-AUC ↑ | Paper |
|---|---|---|---|
| 1 | Multi-RF Fusion with Multi-GNN Blending | 0.8476
±0.0002 | |
| 2 | HyperFusion | 0.8475
±0.0003 | |
| 3 | PAS+FPs | 0.8420
±0.0015 | |
| 9 | GatedGCN | 0.8090
±0.0160 | |
| 109 | GIN | 0.7780
±0.0182 best reported | best today: GRPE: Relative Positional Encoding for Graph Transformer (2022) Difference within reported uncertainty; not counted as underperformance. |
| 145 | GIN+Virtual+P-reg | 0.7712
±0.0114 | This paper |
| 160 | GraphSAGE | 0.7690
±0.0136 | |
| 167 | GIN+P-reg | 0.7677
±0.0141 | This paper |
| 183 | GIN+Virtual | 0.7633
±0.0152 | This paper |
| 184 | GCN | 0.7608
±0.0141 | prev best: Wasserstein Embedding for Graph Learning (ICLR 2020) Improvement within reported uncertainty; not highlighted. |
| 201 | GCN+P-reg | 0.7603
±0.0125 | This paper |
| 210 | GCN+Virtual+P-reg | 0.7581
±0.0161 | This paper |
| 217 | GCN+Virtual | 0.7567
±0.0154 | This paper |
MoleculeNet
| # | Model | ROC-AUC ↑ | Paper |
|---|---|---|---|
| 1 | HIMP | 0.8740
±0.0050 | |
| 2 | GINE w/ VN | 0.8720
±0.0030 | |
| 3 | NaiveGINe+ K=3 w/ VN | 0.8700
±0.0040 | |
| 14 | GCN | 0.8400
±0.0040 best reported | best at pub: Memory-Based Graph Networks (ICLR 2020) best today: Graph convolutions that can finally model local structure (2020) |
| 24 | GIN | 0.8290
±0.0069 best reported | |
| 127 | GCN+Virtual+P-reg | 0.7758
±0.0039 | This paper |
| 130 | GIN+Virtual+P-reg | 0.7751
±0.0068 | This paper |
| 135 | GraphSAGE | 0.7744
±0.0038 | |
| 137 | GCN+Virtual | 0.7742
±0.0067 | This paper |
| 151 | GIN+Virtual | 0.7704
±0.0083 | This paper |
| 189 | GCN+P-reg | 0.7586
±0.0075 | This paper |
| 237 | GIN+P-reg | 0.7490
±0.0059 | This paper |
