Organizations: Harbin Institute of Technology (Shenzhen), Guangdong, China · The Hong Kong University of Science and Technology, Hong Kong SAR, China · Fuzhou University, Fujian, China · The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
The challenges of training and inference in few-shot environments persist in the area of graph representation learning. The quality and quantity of labels are often insufficient due to the extensive expert knowledge required to annotate graph data. In this context, Few-Shot Graph Learning (FSGL) approaches have been developed over the years. Through sophisticated neural architectures and customized training pipelines, these approaches enhance model adaptability to new label distributions. However, compromises in \textcolor{black}{the model's} robustness and interpretability can result in overfitting to noise in labeled data and degraded performance. This paper introduces the first explanation-in-the-loop framework for the FSGL problem, called BAED. We novelly employ the belief propagation algorithm to facilitate label augmentation on graphs. Then, leveraging an auxiliary graph neural network and the gradient backpropagation method, our framework effectively extracts explanatory subgraphs surrounding target nodes. The final predictions are based on these informative subgraphs while mitigating the influence of redundant information from neighboring nodes. Extensive experiments on seven benchmark datasets demonstrate superior prediction accuracy, training efficiency, and explanation quality of BAED. As a pioneer, this work highlights the potential of the explanation-based research paradigm in FSGL.
Figures & tables
Figure 1: Explanation in the loop: a new paradigm for FSGL
Notation
Description
xi
Feature vector of a node vi
ci
A variable representing one potential class of node vi , ci∈C
c^i
Class probability distribution vector of vi predicted by models
ϕi
Prior probability vector of node vi
ϕi(ci)
Prior probability of node vi belonging to one specific class ci
bi
Posterior probability vector of node vi
Table 1: Major notations
Figure 2: BAED: the explanation-based FSGL pipeline
Figure 3: Explanatory subgraphs extracted using gradient backpropagation and edge ranking on the PubMed. Colored backgrounds (red, green, blue) indicate ground-truth node labels; gray nodes are unlabeled. Dashed circles denote the explanatory subgraphs for node A, B, and C, with edge numbers indicating importance rankings. Nodes A and B lie within homogeneous regions of same-label nodes, resulting in clean subgraphs without distracting connections. Node C, positioned near both red and blue nodes, yields a mixed but predominantly blue subgraph, leading to a correct prediction.
Datasets
Cora
Citeseer
PubMed
Wiki
DBLP
Wisconsin
CoauthorCS
Random walk
2.5
3.6
2.2
4.2
2.8
4.9
4.4
BAED
94.6
94.3
87.2
92.3
96.8
93.9
95.5
Table 2: Proportion of Subgraphs with Labels ↑
Datasets
# Classes
# Features
# Edges
# Nodes
Avg. Degree
Cora ( Namata et al., 2016 )
7
1,433
5,429
2,708
3.90
Citeseer ( Bojchevski and Günnemann, 2018 )
6
3,703
4,715
3,312
2.85
PubMed ( Dernoncourt and Lee, 2017 )
3
500
88,676
19,717
4.50
Wiki ( Lim et al., 2021 )
17
4,973
17,981
2,405
14.95
DBLP ( Tang et al., 2008 )
3
1,639
105,734
17,716
11.94
Wisconsin ( Pei et al., 2020 )
5
1,703
515
251
4.10
Table 3: Statistics of Datasets
Datasets
Traditional GNNs
Advanced GNNs
FSGL Models
BAED
Improve.
SAGE
GAT
GIN
GCN
SGC
DLRGAE
HiD
GPN
tsGCN
DCI
SAGE+IG
SAGE+SM
Cora
0.301
0.307
0.269
0.311*
0.301
0.301
0.300
0.251
0.296
0.238
0.515
0.518
66.5%
Citeseer
0.202
0.192
0.215*
0.199
0.189
0.189
0.204
0.199
0.211
0.199
0.769
0.787
266.1%
PubMed
0.400
0.393
0.392
0.396
0.410
0.399
0.484
0.429
0.492*
0.459
0.487
0.507
3.0%
Wiki
0.157
0.152
0.151
0.152
0.152
0.152
0.161*
0.158
0.152
0.139
0.172
0.176
9.3%
DBLP
0.443
0.443
0.443
0.443
0.448
0.443
0.447
0.517*
0.442
0.449
0.690
0.698
24.6%
Table 4: Overall performance comparison on classification ↑
Datesets
BAED-enabled gradient-based explanation models
Non-GNN-based explanation algorithms
Improve.
SM
inpgrad
IG
pgexp
gnnexp
gbp
deconv
GE-L
LIME
DW
LN-L
LP
Cora
0.016
0.010
0.010
0.018
0.018
0.014
0.015
0.015*
0.060
0.017
0.017
-
33.3%
Citeseer
0.046
0.039
0.041
0.040
0.042
0.030
0.031
0.030*
0.274
0.041
0.042
0.045
0.0%
Pubmed
0.273
0.264
0.258
0.393
0.289
0.268
0.261
0.287
0.611
0.384
0.376
0.266*
3.0%
Wiki
1.178
1.178
1.164
1.179
1.177
1.157
1.139
1.149*
1.489
1.180
1.180
-
0.9%
DBLP
1.878
1.799
1.825
2.615
2.050
1.851
1.848
2.135*
3.600
2.612
2.634
2.192
15.7%
Table 5: Overall performance comparison on explainability ↓
Datasets
Number of epochs per second ↑
BP time in BAED (sec.)
Total training time in seconds ↓
Improve.
BAED
GCN
SAGE
tsGCN
DCI
BAED
GCN
SAGE
tsGCN
DCI
Cora
19.46
4.63
1.88
2.81
5.03
1.13
6.1
58.3
76.5
198.0
29.1
78.9%
Citeseer
10.10
5.47
3.40
3.28
3.81
0.11
10.1
31.9
30.3
159.2
32.0
66.3%
PubMed
2.60
2.21
1.66
0.84
2.82
0.06
38.1
51.6
60.0
827.0
653.1
26.8%
Wiki
3.65
3.43
2.21
1.98
5.03
0.15
27.1
29.4
45.2
268.1
32.4
6.4%
DBLP
1.67
1.94
2.60
1.00
1.19
1.11
61.1
50.8
38.7
716.8
218.9
-56.7%
Table 6: Overall performance comparison on efficiency
Datasets
Ablation-1
Ablation-2
Ablation-3
BAED
B AED
BA ED
B A ED
Cora
16.70
30.15
30.15
51.81
Citeseer
8.97
18.16
20.21
78.67
PubMed
47.46
39.39
40.00
50.67
Wiki
8.10
16.12
15.72
12.71
DBLP
55.09
44.26
44.26
69.75
Table 7: Classification Accuracy (%) of Ablation Models
Figure 4: Classification accuracy with different labeling ratios
Size of Explanatory Subgraph
2
3
4
5
6
7
8
Cora
50.4
50.8
51.1
51.8
51.7
49.9
49.7
Citeseer
77.3
78.1
78.1
78.7
78.8
79.5
80.0
Pubmed
46.7
48.3
49.7
50.7
51.0
51.3
51.5
Wiki
12.1
12.3
12.5
12.7
12.9
13.1
13.3
dblp
68.9
68.9
69.8
69.8
70.1
70.1
70.1
Wisconsin
26.1
27.8
29.8
42.0
51.8
51.0
32.7
Table 8: Classification Accuracy (%) with Various Sizes of Explanatory Subgraphs
ϵ
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
accuracy ↑
0.549
0.565
0.582
0.517
0.500
0.529
0.518
0.483
0.582
faithfulness ↓
0.004
0.004
0.004
0.004
0.004
0.005
0.016
0.009
0.010
Table 9: Prediction (accuracy) and explanation (faithfulness) performance of BAED under various ϵ on Cora dataset.
Figure 5: Convergence Curves of BP Process in Label Augmentation. Legend denotes [dataset, No. converged iteration]
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 6: Classification accuracy with different labeling ratios
Datasets
ratio(%)
GNNs
FSGL Models
BAED
SAGE
GAT
GIN
GCN
SGC
DLRGAE
tsGCN
DCI
SAGE+IG
SAGE+SM
Cora
2
0.309
0.193
0.120
0.348*
0.345
0.303
0.237
0.296
0.539
0.603
3
0.317
0.207
0.284
0.393
0.397*
0.285
0.282
0.348
0.616
0.546
Citeseer
2
0.180
0.242
0.219
0.241
0.247
0.221
0.273*
0.254
0.792
0.779
3
0.213
0.240
0.266
0.246
0.255
0.199
0.267
0.272*
0.712
0.732
PubMed
2
0.392
0.392
0.406
0.392
0.584*
0.478
0.549
0.523
0.632
0.618
Appendix
Table 10: Classification performance with different labeling ratios
Datasets
Ratio (%)
BAED-compatible gradient-based explanation models
Non-GNN-based explanation algorithms
SM
inpgrad
IG
pgexp
gnnexp
gbp
deconv
GE-L
LIME
DW
LN-L
LP
Cora
2
0.0200
0.0249
0.0246
0.0222
0.0220
0.0241
0.0238
0.0143*
0.0710
0.0236
0.0226
-
3
0.0164
0.0098
0.0099
0.0183
0.0180
0.0143
0.0155
0.0153*
0.0601
0.0172
0.0174
-
Citeseer
2
0.0145
0.0148
0.0130
0.0205
0.0174
0.0136
0.0136
0.0129*
0.1466
0.0172
0.0176
0.0175
3
0.0457
0.0392
0.0411
0.0403
0.0416
0.0304
0.0313
0.0302
0.2739*
0.0405
0.0416
0.0453
Pubmed
2
0.2512
0.2442
0.2507
0.3418
0.2497
0.2415
0.2332
0.2674
0.6142
0.3371
0.3307
0.2412*
Appendix
Table 11: Explainability performance with different labeling ratios
Figure 7: Convergence Curves of BP Process in Label Augmentation. Labeling Ratio = 2% (Left) and 3% (Right).
Key Laboratory of Symbolic Computation and Knowledge Engineering of the Ministry of Education, College of Computer Science and Technology, Jilin University · School of Mathematical and Computer Sciences, Heriot-Watt University · Department of Information Engineering and Computer Science, University of Trento