From Local Recovery to Unified Generation: Discovering Triple Set in Knowledge Graphs via Observation-Anchored Latent Diffusion
Organizations: Tongji University · The Chinese University of Hong Kong · The Hong Kong University of Science and Technology · Fudan University
Abstract
Triple set prediction (TSP) is to recover missing relational triples in a knowledge graph by predicting the triple set instead of isolated links. Existing approaches predominantly rely on the subgraph-based completion paradigm, where the original graph is first partitioned into local subgraphs which are then independently completed. Such a paradigm suffers from fragmented structural reasoning, limited cross subgraph dependency modeling, and missing predictions across subgraphs. This paper proposes LatentDiff, a novel unified latent generative framework for TSP, which reformulates knowledge graph completion as latent space graph generation. LatentDiff first learns a compact latent representation using a relation-aware residual-quantized knowledge graph autoencoder, which encodes the whole graph into relation-aware latent embeddings, quantizes them with chunked residual codebooks, and reconstructs triples through a factorized decoder. On top of this latent space, we introduce an observation-anchored latent graph diffusion model, where the target latent graph representation is perturbed toward the observed latent. The reverse process recovers missing triples through progressive latent denoising. Experiments on three benchmark datasets show that LatentDiff outperforms the SOTA in terms of F_{tsp} by 5.4 percentage points on average. Code: https://anonymous.4open.science/r/LKGDiff-44A5.
Figures & tables
| Datasets | Entity | Relation | Train | Valid | Test |
|---|---|---|---|---|---|
| Wiki79k | 7,983 | 85 | 57,033 | 6,337 | 15,843 |
| Wiki143k | 13,928 | 109 | 103,415 | 11,490 | 28,727 |
| CFamily | 2,378 | 12 | 16,549 | 1,839 | 4,598 |
| Datasets | Models | Number of Triples in | RS-POWA Metrics | CWA Metrics | ||||||
| Wiki79k | HAKE ( Zhang et al., 2020 ) | 125 87 | 119 83 | 30 7 | 0.246 14.8% | 0.044 0.4% | 0.075 0.3% | 0.004 | 0.240 | 0.074 |
| PairRE ( Chao et al., 2020 ) | 29742 105 | 10217 51 | 2901 7 | 0.191 0.1% | 0.428 0.0% | 0.264 0.2% | 0.187 | 0.097 | 0.158 | |
| AstarNet ( Zhu et al., 2023 ) | 5689 287 | 1750 116 | 1328 52 | 0.496 0.8% | 0.289 0.5% | 0.365 0.2% | 0.143 | 0.233 | 0.258 | |
| ULTRA ( Galkin et al., 2024 ) | 9743 0 | 2945 0 | 1062 0 | 0.235 0.0% | 0.258 0.0% | 0.246 0.0% | 0.104 | 0.109 | 0.153 | |
| GPHT(HAKE) ( Zhang et al., 2024 ) | 209 47 | 191 47 | 44 8 | 0.220 8.0% | 0.053 0.4% | 0.085 1.1% | 0.006 | 0.210 | 0.084 | |
| Models | Number of Triples in | CWA Metrics | |||||
|---|---|---|---|---|---|---|---|
| HAKE ( Zhang et al., 2020 ) | 3186 543 | 3186 543 | 1788 321 | 0.561 1.8% | 0.624 5.9% | 0.591 3.1% | 0.459 |
| PairRE ( Chao et al., 2020 ) | 5732 2062 | 5732 2062 | 1747 694 | 0.305 1.8% | 0.616 13.7% | 0.408 4.9% | 0.338 |
| RGCN ( Schlichtkrull et al., 2018 ) | 30608 3443 | 30608 3443 | 3026 137 | 0.099 6.0% | 0.811 0.5% | 0.176 5.2% | 0.172 |
| CompGCN ( Vashishth et al., 2019 ) | 38931 3745 | 38931 3745 | 2599 47 | 0.067 4.8% | 0.752 0.3% | 0.123 1.7% | 0.119 |
| AstarNet ( Zhu et al., 2023 ) | 2075 360 | 2075 360 | 911 187 | 0.439 1.7% | 0.445 4.6% | 0.442 3.3% | 0.273 |
| Variant | Wiki79k | Wiki143k | CFamily | Avg. |
| LatentDiff | 0.585 | 0.521 | 0.691 | 0.599 |
| LatentDiff-Subgraph | 0.539 | 0.472 | 0.653 | 0.555 |
| w/o Relational view Attention | 0.576 | 0.495 | 0.674 | 0.582 |
| w/o CRVQ (VQ-VAE) | 0.030 | 0.075 | 0.455 | 0.187 |
| w/o Quantization (Vanilla AE) | 0.498 | 0.414 | 0.332 | 0.415 |
| w/o Factorized Decoder | 0.557 | 0.481 | 0.659 | 0.566 |
| Dataset | #Train | #Retained | #Uncovered | Uncovered Ratio | #Test | #Same-subgraph | #Partition-boundary | Boundary Ratio |
|---|---|---|---|---|---|---|---|---|
| CFamily | 16,549 | 16,514 | 35 | 0.21% | 4,598 | 4,551 | 47 | 1.02% |
| Wiki79k | 57,033 | 53,937 | 3,096 | 5.43% | 15,843 | 12,452 | 3,391 | 21.40% |
| Wiki143k | 103,415 | 88,984 | 14,431 | 13.95% | 28,727 | 16,781 | 11,946 | 41.58% |
| Target Triple | GPHT | DiffTSP | LatentDiff |
|---|---|---|---|
| ( October , follows, September ) | Missed | Missed | Recalled |
| ( 2006 Asian Games , follows, 2002 Asian Games ) | Missed | Missed | Recalled |
| ( Châlons-en-Champagne , twinned with, Neuss ) | Missed | Missed | Recalled |
| ( Épinal , located in, Vosges ) | Missed | Missed | Recalled |
| ( Braga , shares border with, Guimarães ) | Missed | Missed | Recalled |
| ( Bonn , country, Weimar Republic ) | Missed | Missed | Recalled |
| Dataset | Method | Recalled | |
|---|---|---|---|
| Wiki79k | GPHT | 0.000 | |
| DiffTSP | 0.000 | ||
| LatentDiff | 0.229 | ||
| Wiki143k | GPHT | 0.000 | |
| DiffTSP | 0.000 | ||
| LatentDiff | 0.195 |
| Dataset | GPHT | DiffTSP | LatentDiff | Speedup |
|---|---|---|---|---|
| CFamily | 46.25 | 8.13 | 1.64 | 4.9 |
| Wiki79k | 151.94 | 83.77 | 12.79 | 6.5 |
| Wiki143k | 583.69 | 101.07 | 35.93 | 2.8 |
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
| Hyperparameter | CFamily | Wiki79k | Wiki143k |
| Stage-I Training | |||
| Encoder hidden dimension | 64 | 64 | 32 |
| Chunks of CRVQ | 4 | 4 | 4 |
| Number of residual quantizers | 4 | 4 | 2 |
| Latent dimension | 16 | 16 | 16 |
| Codebook size | 1024 | 1024 | 2048 |
| Variant | CFamily | Wiki79k | Wiki143k |
|---|---|---|---|
| LatentDiff | 0.9703 | 0.6918 | 0.7145 |
| w/o Relational view Attention | 0.9057 | 0.6229 | 0.6927 |
| w/o CRVQ (VQ-VAE) | 0.4591 | 0.0575 | 0.1098 |
| w/o Quantization (Vanilla AE) | 0.9898 | 0.7187 | 0.7339 |
| w/o Factorized Decoder | 0.8895 | 0.5891 | 0.6219 |
| Dataset | Prediction Time (s) | Peak Memory (MB) | ||
|---|---|---|---|---|
| CFamily | 0.72 | 1.64 | 2,136 | 2,136 |
| Wiki79k | 12.79 | 22.96 | 12,366 | 12,366 |
| Wiki143k | 35.93 | 45.76 | 19,872 | 19,872 |
KG Completion
Knowledge graph completion (KGC) predicts missing entities, relations, or facts from structured graphs and supporting evidence.
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