KG Inductive Link Prediction Challenge (ILPC) 2022

This repository introduces the ILPC'22 Small and ILPC'22 Large datasets for benchmarking inductive link prediction models and outlines the 2022 incarnation of the Inductive Link Prediction Challenge (ILPC).

🗄️ Datasets

While in transductive link prediction, the training and inference graph are the same (and therefore contain the same entities), in inductive link prediction, there is a disjoint inference graph that potentially contains new, unseen entities.

For this challenge, we sampled two datasets from Wikidata, the largest publicly available and open KG. Inductive link prediction implies training a model on one graph (denoted as training) and performing inference, eg, validation and test, over a new graph (denoted as inference).

Dataset creation principles:

• Represents a real-world KG used in many NLP and ML tasks (Wikidata)
• Larger than existing benchmarks
• Allows for fast iteration and hypothesis testing - we sampled two datasets, small and large, that vary in sizes of training and inference graphs.
• The ratio of training / inference graph sizes is challenging for modern GNNs.
• Training graph is a connected component
• Inference graph is a connected component

Both the small and large variants of the dataset can be found in the data folder of this repository. Each contains four splits corresponding to the diagram:

• train.txt - the training graph on which you are supposed to train a model
• inference.txt - the inductive inference graph disjoint with the training one - that is, it has a new non-overlapping set of entities, the missing links are sampled from this graph
• inductive_validation.txt - validation set of triples to predict, uses entities from the inference graph
• inductive_test.txt - test set of triples to predict, uses entities from the inference graph
• a hold-out test set of triples - kept by the organizers for the final ranking 😉 , uses entities from the inference graph

ILPC'22 Small

Split	Entities	Relations	Triples
Train	10,230	96	78,616
Inference	6,653	96 (subset)	20,960
Inference validation	6,653	96 (subset)	2,908
Inference test	6,653	96 (subset)	2,902
Hold-out test set	6,653	96 (subset)	2,894

ILPC'22 Large

Split	Entities	Relations	Triples
Train	46,626	130	202,446
Inference	29,246	130 (subset)	77,044
Inference validation	29,246	130 (subset)	10,179
Inference test	29,246	130 (subset)	10,184
Hold-out test set	29,246	130 (subset)	10,172

🏅 Challenge

The Challenge aims to streamline community efforts in the emerging area of representation learning techniques beyond shallow entity embeddings. We invite submissions proposing new inductive models as well as extending baseline models to achieve higher performance.

We use the following rank-based evaluation metrics:

• MRR (Inverse Harmonic Mean Rank) - higher is better, range [0, 1]
• Hits @ K (H@K; with K as one of {1, 3, 5, 10, 100}) - higher is better, range [0, 1]
• AMRI (Adjusted Arithmetic Mean Rank Index) - higher is better, compares model scoring against random scoring, range [-1, 1]. AMRI=0 means the model is not better than random scoring.

Making a submission:

1. Fork the repo
2. Train your inductive link prediction model
3. Save the model weights using the --save flag
4. Upload model weights on GitHub or other platforms (Dropbox, Google Drive, etc)
5. Open an issue in this repo with the link to your repo, performance metrics, and model weights

🎸 Baselines

We provide an example workflow in main.py for training and evaluating two variants of the NodePiece model using PyKEEN:

• InductiveNodePiece - plain tokenizer + tokens MLP encoder to bootstrap node representations. Fast.
• InductiveNodePieceGNN - everything above + an additional 2-layer CompGCN message passing encoder. Slower but performs better.

The example can be run with python main.py and the options can be listed with python main.py --help.

Installation Instructions

Main requirements:

• python >= 3.9
• torch >= 1.10

You will need PyKEEN 1.8.0 or newer.

$ pip install pykeen

By the time of creation of this repo 1.8.0 is not yet there, but the latest version from sources contains everything we need

$ pip install git+https://github.com/pykeen/pykeen.git

If you plan to use GNNs (including the InductiveNodePieceGNN baseline) make sure you install torch-scatter and torch-geometric compatible with your python, torch, and CUDA versions.

Running the code on a GPU is strongly recommended.

Baseline Performance on Small Dataset

We report the performance of both variants of the NodePiece model on the small variant of the dataset after running the following:

• InductiveNodePieceGNN (32d, 50 epochs, 24K params) - NodePiece (5 tokens per node, MLP aggregator) + 2-layer CompGCN with DistMult composition function + DistMult decoder. Training time: 77 min*

  $ python main.py --dataset small -d 32 -e 50 -n 16 -m 2.0 -lr 0.0001 --gnn

• InductiveNodePiece (32d, 50 epochs, 15.5K params) - NodePiece (5 tokens per node, MLP aggregator) + DistMult decoder. Training time: 6 min*

  $ python main.py --dataset small -d 32 -e 50 -n 16 -m 5.0 -lr 0.0001

Model	MRR	H@100	H@10	H@5	H@3	H@1	AMRI
InductiveNodePieceGNN	0.1326	0.4705	0.2509	0.1899	0.1396	0.0763	0.730
InductiveNodePiece	0.0381	0.4678	0.0917	0.0500	0.0219	0.007	0.666

Baseline Performance on Large Dataset

We report the performance of both variants of the NodePiece model on the large variant of the dataset after running the following:

• InductiveNodePieceGNN (32d, 53 epochs, 24K params) - NodePiece (5 tokens per node, MLP aggregator) + 2-layer CompGCN with DistMult composition function + DistMult decoder. Training time: 8 hours*

  $ python main.py --dataset large -d 32 -e 53 -n 16 -m 20.0 -lr 0.0001 --gnn

• InductiveNodePiece (32d, 17 epochs, 15.5K params) - NodePiece (5 tokens per node, MLP aggregator) + DistMult decoder. Training time: 5 min*

  $ python main.py --dataset large -d 32 -e 17 -n 16 -m 15.0 -lr 0.0001

Model	MRR	H@100	H@10	H@5	H@3	H@1	AMRI
InductiveNodePieceGNN	0.0705	0.374	0.1458	0.0990	0.0730	0.0319	0.682
InductiveNodePiece	0.0651	0.287	0.1246	0.0809	0.0542	0.0373	0.646

* Note: All models were trained on a single RTX 8000. Average memory consumption during training is about 2 GB VRAM on the small dataset and about 3 GB on large.

👋 Attribution

⚖️ License

The code in this package is licensed under the MIT License. The datasets in this repository are licensed under the Creative Commons Zero license. The trained models and their weights are licensed under the Creative Commons Zero license.

📖 Citation

If you use the ILPC'22 datasets in your work, please cite the following:

@article{Galkin2022,
  archivePrefix = {arXiv},
  arxivId = {2203.01520},
  author = {Galkin, Mikhail and Berrendorf, Max and Hoyt, Charles Tapley},
  eprint = {2203.01520},
  month = {mar},
  title = {{An Open Challenge for Inductive Link Prediction on Knowledge Graphs}},
  url = {http://arxiv.org/abs/2203.01520},
  year = {2022}
}

🎁 Support

This project has been supported by several organizations (in alphabetical order):

• Harvard Program in Therapeutic Science - Laboratory of Systems Pharmacology
• Ludwig-Maximilians-Universität München
• Mila
• Munich Center for Machine Learning (MCML)

🏦 Funding

This project has been funded by the following grants:

Funding Body	Program	Grant
DARPA	Young Faculty Award (PI: Benjamin Gyori)	W911NF2010255
German Federal Ministry of Education and Research (BMBF)	Munich Center for Machine Learning (MCML)	01IS18036A
Samsung	Samsung AI Grant	-