11 Graph representation learning and graph neural network

 

This chapter covers

  • Graph representation learning and its role in scaling machine learning on graphs
  • How deep learning automates the feature engineering process
  • The fundamentals of graph embeddings and their applications
  • Introducing Graph Neural Networks (GNNs)

In chapters 9 and 10, we explored the fundamental concepts of machine learning on graphs, demonstrating how these techniques can solve complex tasks like node classification, link prediction, and community detection. We showed how manual feature engineering can effectively capture graph properties and relationships to power downstream machine learning tasks through carefully crafted examples and hands-on implementations. These approaches provided valuable insights into what makes graph-based machine learning work, offering complete transparency into how our models make decisions.

11.1 Embeddings in graph representation learning

11.1.1 Understanding graph embeddings: From discrete to continuous

11.1.2 Real-World applications and examples

11.2 The encoder-decoder model

11.2.1 The Encoder: Converting graph structure to vectors

11.2.2 The Decoder: Reconstructing graph properties

11.2.3 The power of the framework

11.2.4 Node2vec: an example of encoder-decoder framework

11.3 Shallow embeddings: a first approach to graph representation

11.3.1 Understanding shallow embeddings

11.3.2 Limitations of shallow embeddings

11.4 Embeddings in knowledge graphs

11.4.1 Loss function

11.4.2 Multi-Relationship decoder

11.5 Message passing and Graph Neural Networks (GNNs)

11.5.1 The message passing framework: a neural conversation

11.5.2 Motivation and intuition: why message passing works

11.5.3 The basic GNN model

11.5.4 Message passing with self-loops

11.6 Generalized aggregation and update methods

11.6.1 Neighborhood normalization

11.6.2 Neighborhood attention

11.6.3 Multi-head attention and transformer connections

11.6.4 Generalized update methods

11.7 The synergy of GNNs and LLMs

11.8 Summary

11.9 References