Structure Pretraining and Prompt Tuning for Knowledge Graph Transfer

Original Paper: https://arxiv.org/abs/2303.03922

By: Wen Zhang, Yushan Zhu, Mingyang Chen, Yuxia Geng, Yufeng Huang, Yajing Xu, Wenting Song, Huajun Chen

Abstract:

Knowledge graphs (KG) are essential background knowledge providers in many tasks. When designing models for KG-related tasks, one of the key tasks is to devise the Knowledge Representation and Fusion (KRF) module that learns the representation of elements from KGs and fuses them with task representations. While due to the difference of KGs and perspectives to be considered during fusion across tasks, duplicate and ad hoc KRF modules design are conducted among tasks. In this paper, we propose a novel knowledge graph pretraining model KGTransformer that could serve as a uniform KRF module in diverse KG-related tasks. We pretrain KGTransformer with three self-supervised tasks with sampled sub-graphs as input. For utilization, we propose a general prompt-tuning mechanism regarding task data as a triple prompt to allow flexible interactions between task KGs and task data. We evaluate pretrained KGTransformer on three tasks, triple classification, zero-shot image classification, and question answering. KGTransformer consistently achieves better results than specifically designed task models. Through experiments, we justify that the pretrained KGTransformer could be used off the shelf as a general and effective KRF module across KG-related tasks. The code and datasets are available at

this https URL

Summary Notes

Simplified Blog Post: Transforming AI with KGTransformer for Knowledge Graphs

Knowledge Graphs (KGs) are a critical part of AI, used in everything from answering your questions to helping recognize images.

But making these graphs work well for different AI tasks has been tough. The key issue?

There isn't a one-size-fits-all method for how these graphs are used and combined in AI projects.

This blog looks at an innovative solution called KGTransformer, introduced by Wen Zhang and colleagues, which aims to solve this problem through structure pretraining and prompt tuning.

The Issue: One Tool for All Tasks

KGs store facts in a structured way but adapting them for various AI tasks hasn't been straightforward.

The main challenge has been the lack of a universal method to efficiently learn from and apply KGs across different tasks, leading to inefficient and overly complex AI systems.

KGTransformer: A Unified Approach

KGTransformer offers a promising solution. It's designed to work as a universal method for AI tasks, capable of handling specific KGs and data flexibly. Here's what sets it apart:

KG Representation Evolved

• Embedding-based: Learning dense vectors for entities and relations.
• Structure-based: Using graph neural networks to understand the graph's structure.
• Hybrid-based: Combining embeddings with structural learning.
• Transformer-based: Applying transformer architecture to KGs for deeper insights.

KG Fusion Methods

• Out-of-the-box: Directly using pre-trained KG embeddings in models.
• End-to-end: Integrating specific KG encoders with task models for cohesive learning.

The Role of Pretraining

Pretraining, like in NLP models BERT and GPT, shows the benefits of learning general features that can be fine-tuned for particular tasks.

This concept is applied to KGs to capture broad knowledge that can be adapted to different tasks, making models more versatile and efficient.

How KGTransformer Works

Architecture

KGTransformer has a multi-layer design that processes KG triples, allowing for nuanced interactions and a deep understanding of relationships.

Pretraining on Sub-graphs

It uses pretraining tasks like Masked Entity Modeling and Masked Relation Modeling on sub-graphs. This helps the model learn a wide range of knowledge from KGs.

Prompt Tuning for Adaptation

A key feature is prompt tuning, where task-specific data is transformed into triple-like prompts. This lets the pretrained model quickly adapt to new tasks with minimal retraining.

Testing and Results

Experiments showed KGTransformer performing better than specialized models and baselines in several tasks, including triple classification, zero-shot image classification, and question answering. This proves the effectiveness of structure pretraining and prompt tuning in KG contexts.

Conclusion: Advancing AI with KGs

KGTransformer represents a big step forward in using KGs more efficiently in AI.

By solving the problem of universal knowledge representation and fusion, it opens the door to scalable, efficient, and adaptable AI systems.

This method's success highlights the potential of transfer learning in KG settings and the benefits of a unified approach across different tasks.

Key Takeaways

• KGTransformer captures transferable knowledge from KGs.
• It introduces prompt tuning for easy task adaptation.
• Tests confirm its effectiveness across various KG-related tasks.

This research points towards a more integrated and efficient future for AI applications, setting a new standard for how we use and benefit from knowledge graphs.