Heterogeneous Graph Neural Network on Semantic Tree

Abstract

The recent past has seen an increasing interest in Heterogeneous Graph Neural Networks (HGNNs), since many real-world graphs are heterogeneous in nature, from citation graphs to email graphs. However, existing methods ignore a tree hierarchy among metapaths, naturally constituted by different node types and relation types. In this paper, we present HETTREE, a novel HGNN that models both the graph structure and heterogeneous aspects in a scalable and effective manner. Specifically, HETTREE builds a semantic tree data structure to capture the hierarchy among metapaths. To effectively encode the semantic tree, HETTREE uses a novel subtree attention mechanism to emphasize metapaths that are more helpful in encoding parent-child relationships. Moreover, HETTREE proposes carefully matching pre-computed features and labels correspondingly, constituting a complete metapath representation. Our evaluation of HETTREE on a variety of real-world datasets demonstrates that it outperforms all existing baselines on open benchmarks and efficiently scales to large real-world graphs with millions of nodes and edges.