Non-Exemplar Continual Graph Learning (NECGL) seeks to eliminate the privacy risks intrinsic to rehearsal-based paradigms by retaining solely class-level prototype representations rather than raw graph examples for mitigating catastrophic forgetting. However, this design choice inevitably precipitates feature drift. As a nascent alternative, Analytic Continual Learning (ACL) capitalizes on the intrinsic generalization properties of frozen pre-trained models to bolster continual learning performance. Nonetheless, a key drawback resides in the pronounced attenuation of model plasticity. To surmount these challenges, we propose Analytic Drift Resister (ADR), a novel and theoretically grounded NECGL framework. ADR exploits iterative backpropagation to break free from the frozen pre-trained constraint, adapting to evolving task graph distributions and fortifying model plasticity. Since parameter updates trigger feature drift, we further propose Hierarchical Analytic Merging (HAM), performing layer-wise merging of linear transformations in Graph Neural Networks (GNNs) via ridge regression, thereby ensuring absolute resistance to feature drift. On this basis, Analytic Classifier Reconstruction (ACR) enables theoretically zero-forgetting class-incremental learning. Empirical evaluation on four node classification benchmarks demonstrates that ADR maintains strong competitiveness against existing state-of-the-art methods.
Figures & tables
Fig. 1: A schematic overview of different Continual Graph Learning paradigms.
Fig. 2: The overall pipeline of the proposed ADR. (a) Upon the arrival of a new task Tt , the model adapts freely to the corresponding graph distribution via iterative BP without any imposed regularization. (b) HAM performs analytic merging of the layer-wise linear transformations of all historical task encoders, unifying their latent representation spaces. (c) ACR exploits the merged encoder to derive linear classifier weights, enabling robust class-incremental learning.
Datasets
CS-CL
CoraFull-CL
Arxiv-CL
Reddit-CL
# nodes
18333
19793
169343
232965
# edges
163788
126842
1166243
114615892
# features
6805
8710
128
602
# all classes
15
70
40
40
# base classes
5
30
20
20
# incremental classes
10
40
20
20
TABLE I: Key statistical characteristics of four node classification benchmarks.
Methods
CS-CL
CoraFull-CL
Arxiv-CL
Reddit-CL
Aavg (%)
Af (%)
Aavg (%)
Af (%)
Aavg (%)
Af (%)
Aavg (%)
Af (%)
Joint
-
88.92 ± 0.25
-
61.62 ± 0.26
-
42.11 ± 0.20
-
79.82 ± 0.69
Bare
53.24 ± 1.83
34.54 ± 6.39
17.55 ± 0.15
3.75 ± 0.90
18.16 ± 0.10
8.99 ± 0.02
40.47 ± 0.91
12.64 ± 1.97
LWF
62.59 ± 1.40
38.40 ± 2.30
18.53 ± 0.75
6.91 ± 1.17
17.64 ± 0.18
8.97 ± 0.05
37.73 ± 0.76
12.76 ± 2.45
EWC
72.76 ± 3.04
49.67 ± 5.28
20.23 ± 0.40
5.44 ± 1.92
17.01 ± 0.15
8.91 ± 0.03
40.93 ± 0.74
8.82 ± 0.04
MAS
75.22 ± 2.02
66.91 ± 2.09
19.21 ± 0.29
9.09 ± 1.83
17.68 ± 0.49
8.81 ± 0.51
53.02 ± 3.55
33.11 ± 4.24
TABLE II: Performance comparison on the four benchmarks. The best results are highlighted in bold, and the second-best results are underlined.
Variants
CS-CL
CoraFull-CL
Arxiv-CL
Reddit-CL
Aavg (%)
Af (%)
Aavg (%)
Af (%)
Aavg (%)
Af (%)
Aavg (%)
Af (%)
w/o HAM
52.28 ± 1.27
36.63 ± 2.92
17.36 ± 0.19
7.65 ± 0.99
20.07 ± 0.06
9.01 ± 0.02
43.83 ± 0.67
17.43 ± 1.75
w/ Simple Averaging
65.08 ± 1.31
48.79 ± 1.91
31.83 ± 0.48
24.75 ± 0.95
23.23 ± 0.20
15.17 ± 0.37
69.29 ± 2.12
48.23 ± 1.89
w/ Fisher Merging
69.07 ± 2.58
58.01 ± 5.32
27.68 ± 0.66
18.64 ± 1.39
26.06 ± 1.33
10.15 ± 0.23
68.53 ± 2.78
48.42 ± 3.25
w/ MAGMAX Merging
67.23 ± 0.78
57.34 ± 3.98
31.08 ± 1.16
21.91 ± 1.82
21.66 ± 0.24
9.64 ± 0.20
70.15 ± 1.03
50.81 ± 3.52
ADR
90.71 ± 0.22
87.21 ± 0.42
67.52 ± 0.83
60.03 ± 1.22
39.66 ± 0.43
34.74 ± 0.21
82.52 ± 0.21
75.45 ± 0.40
TABLE III: Ablation studies of HAM on the four benchmarks. The best results are highlighted in bold.
Fig. 3: Model plasticity comparison of our ADR versus existing ACL methods on the four benchmarks.
Fig. 4: Feature drift visualization of EFC, DPCR, and ADR on the base task graph G0 across CS-CL and CoraFull-CL benchmarks.
Fig. 5: Visualization of the grid search over hyperparameters α and γ , with Aavg reported.
Fig. 6: Learning dynamics over the task streams on CS-CL, CoraFull-CL, Arxiv-CL, and Reddit-CL, with At reported for all tasks.
Fig. 7: Left three panels: Performance matrices for ACIL, DS-AL, and ADR on the test set of Arxiv-CL. Rightmost panel: Quantification of intra-task class imbalance in the training set of Arxiv-CL.