Neurochaos Learning (NL) has shown promise in recent times over traditional deep learning due to its two key features: ability to learn from small sized training samples, and low compute requirements. In prior work, NL has been implemented and extensively tested on separable and time series data, and demonstrated its superior performance on both classification and regression tasks. In this paper, we investigate the next step in NL, viz., applying NL to linked data, in particular, data that is represented in the form of knowledge graphs. We integrate linked data into NL by implementing node aggregation on knowledge graphs, and then feeding the aggregated node features to the simplest NL architecture: ChaosNet. We demonstrate the results of our implementation on homophilic graph datasets as well as heterophilic graph datasets of verying heterophily. We show better efficacy of our approach on homophilic graphs than on heterophilic graphs. While doing so, we also present our analysis of the results, as well as suggestions for future work.
Figures & tables
Figure 1: Neurochaos-based feature transformation and classification pipeline.
Dataset
Nodes
Features
Edges
Classes
Hom.
Het.
Graph Property
Cora
2,708
1,433
5,429
7
0.810
0.190
Highly homophilic
Citeseer
3,327
3,703
4,732
6
0.738
0.262
Moderately homophilic
PubMed
19,717
500
44,338
3
0.802
0.198
Moderately homophilic
Actor
7,600
932
30,019
5
0.219
0.781
Highly heterophilic
Cornell
183
1,703
295
5
0.131
0.869
Highly heterophilic
Wisconsin
251
1,703
499
5
0.196
0.804
Highly heterophilic
Table 1: Quantitative summary of linked datasets used in this study.
Dataset
Graph Property
Q
B
ϵ
Train Macro F1
Test Macro F1
Cora
Highly Homophilic
0.52
0.75
0.10
0.828
0.844
PubMed
Homophilic
0.524
0.759
0.0987
0.78
0.76
Citeseer
Homophilic
0.53
0.76
0.0985
0.705
0.732
Cornell
Partial Homo/Hetero
0.524
0.76
0.0985
0.53
0.43
Wisconsin
Partial Homo/Hetero
0.525
0.7625
0.0975
0.58
0.57
Actor
Highly Heterophilic
0.44
0.66
0.108
0.265
0.265
Table 2: Mean Node Aggregation Results on All Datasets
Dataset
Graph Property
Q
B
ϵ
Train Macro F1
Test Macro F1
Cora
Homophilic
0.18
0.14
0.18
0.308
0.23
Actor
Heterophilic
0.44
0.66
0.108
0.232
0.25
Cornell
Partial Homo/Hetero
0.13
0.15
0.20
0.263
0.232
Table 3: H2GNN Results on Selected Datasets
Q
B
ϵ
TrainMacro F1
0.52
0.75
0.10
0.8437
0.50
0.70
0.09
0.8130
0.49
0.75
0.07
0.8026
Table 4: Best ChaosNet Runs on the Cora Dataset
Figure 2: 3D visualization of macro F1-score across the ChaosNet hyperparameter space on the Cora dataset