Link sign prediction (LSP) aims to infer the positive or negative polarity of unobserved links in signed networks. Signed Graph Neural Networks (SGNNs) usually rely on signed-graph structural priors, including structural balance and homophily-like similarity, to guide message passing and prediction. These priors describe population-level tendencies, not guarantees for individual target edges. Their failures are especially costly under severe sign imbalance, where errors on minority and locally conflicting relations are harder to detect and correct. We propose Polarity-Asymmetric Structural Calibration (PASC), a target-edge structural-prior calibration framework for signed link prediction. PASC constructs a structure-only prior representation, estimates a target-edge structural prior score, and compares this score with a local signed-context cue to derive a conflict residual. The residual calibrates signed attention aggregation, target-edge gated fusion, and regime-adaptive optimization. Experiments on five real-world signed network datasets show that PASC consistently achieves the best Macro-F1 among representative baselines, with competitive AUC, Binary-F1, and Micro-F1. Structural-shift experiments further suggest reduced dependence on dense-neighborhood and local-closure shortcuts. Source code is available at https://github.com/iqqGGGGGGG/PASC-for-LSP.
Figures & tables
Fig. 1: Example of target-edge structural-prior unreliability. Alice and Carol share a positive neighbor Bob, so structural balance suggests a positive relation. Their local signed context, however, may provide conflicting evidence. Structural priors capture population-level tendencies but need not be reliable for every target edge.
Triads
Prior
(+,+)
(+,−)/(−,+)
(−,−)
Posterior
+
−
+
−
+
−
Datasets
Bitcoin-Alpha
95.7%
4.3%
63.5%
36.5%
86.6%
13.4%
Bitcoin-OTC
95.9%
4.1%
39.3%
60.7%
90.2%
9.8%
Wiki-RfA
88.1%
11.9%
70.8%
29.2%
66.9%
33.1%
Slashdot
94.9%
5.1%
46.5%
53.5%
68.5%
31.5%
Epinions
96.5%
3.5%
53.5%
46.5%
69.7%
30.3%
TABLE I: Prior-Posterior Statistics of Triangles in Signed Networks
Fig. 2: Architecture of the PASC framework for link sign prediction. PASC estimates target-edge structural prior scores, derives conflict residuals from local signed-context cues, and uses residual-guided aggregation, regime-adaptive conflict-residual optimization (PASC-S and PASC-H), and target-edge gated fusion to calibrate structural reliance under different graph regimes.
Dataset
Nodes
Edges
Pos links
Neg links
Pos/Neg
Bitcoin-Alpha 1
3,782
24,185
22,649
1,536
14.7:1
Bitcoin-OTC 1
5,881
35,591
32,028
3,563
9.0:1
Wiki-RfA 1
11,259
178,096
138,813
39,283
3.5:1
Slashdot 1
84,140
549,201
425,071
124,130
3.4:1
Epinions 1
131,827
841,371
717,667
123,704
5.8:1
TABLE II: Statistics of the datasets used in our experiments.
Dataset
Metrics
nSNE
SGCN
SNEA
SDGNN
RSGNN
SPMF
TrustSGCN
CFSE
PASC
Bitcoin-Alpha
AUC
84.25 ± 2.72
88.57 ± 0.19
89.20 ± 1.60
90.29 ± 1.27
79.68 ± 0.71
90.15 ± 0.28
86.72 ± 0.93
93.37 ± 0.40
93.61 ± 0.53
Binary-F1
94.07 ± 5.01
97.07 ± 0.05
93.60 ± 0.47
97.23 ± 0.30
94.81 ± 0.08
97.15 ± 0.11
97.00 ± 0.04
97.81 ± 0.02
97.85 ± 0.03
Micro-F1
89.37 ± 8.30
94.35 ± 0.11
88.55 ± 0.81
94.75 ± 0.58
90.56 ± 0.15
94.61 ± 0.21
94.30 ± 0.06
95.84 ± 0.04
95.95 ± 0.06
Macro-F1
57.76 ± 9.71
60.28 ± 0.92
69.44 ± 1.61
72.91 ± 4.32
71.18 ± 0.49
73.24 ± 0.11
69.00 ± 0.93
79.75 ± 0.32
81.30 ± 0.36
Bitcoin-OTC
AUC
90.02 ± 0.97
91.63 ± 0.09
87.90 ± 0.68
89.69 ± 1.12
81.04 ± 0.30
89.33 ± 0.40
88.92 ± 0.54
95.00 ± 0.81
94.98 ± 0.04
Binary-F1
96.25 ± 0.42
96.21 ± 0.13
92.31 ± 0.57
95.97 ± 0.33
92.69 ± 0.27
95.77 ± 0.03
95.57 ± 0.28
97.34 ± 0.11
97.53 ± 0.13
TABLE III: Performance comparison on five real-world datasets (mean ± standard deviation). The PASC column reports the variant chosen by the pre-defined training-graph rule used in Fig. 3 .
Fig. 3: Variant Adaptability comparison of PASC-S and PASC-H under different signed-topology regimes.
Fig. 4: Ablation study of PASC. Panels (a) and (b) report the degradation ( Δ% ) in AUC and Macro-F1 when each component is removed.
Fig. 5: Sensitivity analysis of λ1 and λ2 on Wiki-RfA and Slashdot, showing stable AUC and Macro-F1 across loss-weight settings.
Dataset
Metrics
nSNE
SGCN
SNEA
SDGNN
RSGNN
SPMF
TrustSGCN
CFSE
PASC
Bitcoin-Alpha
AUC
69.53 ± 2.93
80.60 ± 1.58
83.10 ± 0.70
80.71 ± 0.81
74.31 ± 0.04
83.40 ± 0.54
79.89 ± 0.23
77.94 ± 1.39
84.52 ± 0.17
Macro-F1
49.80 ± 1.97
54.89 ± 6.16
70.17 ± 0.58
63.19 ± 3.48
66.61 ± 0.83
71.16 ± 0.19
59.46 ± 1.93
60.92 ± 2.22
72.05 ± 0.35
Bitcoin-OTC
AUC
76.48 ± 7.61
88.01 ± 0.10
85.46 ± 0.10
87.01 ± 0.13
79.34 ± 0.18
88.10 ± 0.35
87.77 ± 0.09
78.26 ± 5.80
89.09 ± 0.03
Macro-F1
53.46 ± 7.69
75.71 ± 0.14
74.66 ± 0.28
75.67 ± 0.11
71.61 ± 0.28
76.75 ± 0.25
74.26 ± 0.20
68.10 ± 3.47
80.06 ± 0.26
Wiki-RfA
AUC
69.46 ± 1.30
78.81 ± 1.19
79.36 ± 0.16
77.27 ± 0.87
66.62 ± 1.17
78.84 ± 0.15
77.08 ± 3.01
72.25 ± 4.89
79.70 ± 0.13
Macro-F1
50.08 ± 9.25
67.02 ± 1.25
66.13 ± 0.05
69.23 ± 0.21
53.81 ± 0.62
69.23 ± 0.18
65.48 ± 3.83
62.83 ± 1.48
69.24 ± 0.21
TABLE IV: Performance comparison under the Degree-Shift structural-shift protocol. For space, structural-shift tables report AUC and Macro-F1. Binary-F1 and Micro-F1 show similar trends and are omitted.
Dataset
Metrics
nSNE
SGCN
SNEA
SDGNN
RSGNN
SPMF
TrustSGCN
CFSE
PASC
Bitcoin-Alpha
AUC
66.02 ± 5.45
79.98 ± 0.70
79.17 ± 0.87
79.77 ± 1.50
73.37 ± 0.35
79.00 ± 0.43
80.09 ± 2.12
76.10 ± 1.27
81.67 ± 0.15
Macro-F1
49.44 ± 1.68
60.74 ± 1.07
65.82 ± 0.62
62.49 ± 3.51
62.19 ± 0.11
65.48 ± 0.49
60.38 ± 2.60
59.48 ± 1.97
67.53 ± 0.38
Bitcoin-OTC
AUC
73.00 ± 2.18
83.86 ± 0.21
82.79 ± 2.38
83.87 ± 0.21
76.38 ± 0.02
83.20 ± 0.95
84.05 ± 0.21
80.66 ± 1.99
85.33 ± 0.10
Macro-F1
59.85 ± 5.63
70.81 ± 0.71
72.80 ± 1.57
69.35 ± 0.45
69.68 ± 0.21
71.84 ± 0.47
65.48 ± 0.93
69.90 ± 0.92
74.36 ± 0.54
Wiki-RfA
AUC
80.28 ± 2.19
80.52 ± 0.10
84.12 ± 0.20
81.99 ± 0.62
71.48 ± 0.10
80.95 ± 0.07
80.47 ± 0.71
83.00 ± 0.87
84.19 ± 0.23
Macro-F1
44.53 ± 4.91
69.06 ± 2.20
75.08 ± 0.28
71.66 ± 0.68
71.91 ± 0.32
73.66 ± 0.07
64.89 ± 0.39
73.95 ± 0.82
75.28 ± 0.51
TABLE V: Performance comparison under the Structural-Shortcut-Shift structural-shift protocol. For space, structural-shift tables report AUC and Macro-F1. Binary-F1 and Micro-F1 show similar trends and are omitted.