OntoTKGE: Ontology-Enhanced Temporal Knowledge Graph Extrapolation

TL;DR

OntoTKGE introduces an ontology-guided encoder-decoder framework that enhances temporal knowledge graph extrapolation by leveraging hierarchical ontological knowledge to address entity sparsity.

Contribution

The paper presents a novel framework that integrates ontological knowledge into TKG extrapolation models, improving their performance and addressing entity sparsity issues.

Findings

Significantly improves TKG extrapolation performance across four datasets.

Outperforms many state-of-the-art baseline methods.

Flexible framework adaptable to various TKG models.

Abstract

Temporal knowledge graph (TKG) extrapolation is an important task that aims to predict future facts through historical interaction information within KG snapshots. A key challenge for most existing TKG extrapolation models is handling entities with sparse historical interaction. The ontological knowledge is beneficial for alleviating this sparsity issue by enabling these entities to inherit behavioral patterns from other entities with the same concept, which is ignored by previous studies. In this paper, we propose a novel encoder-decoder framework OntoTKGE that leverages the ontological knowledge from the ontology-view KG (i.e., a KG modeling hierarchical relations among abstract concepts as well as the connections between concepts and entities) to guide the TKG extrapolation model's learning process through the effective integration of the ontological and temporal knowledge, thereby enhancing entity embeddings. OntoTKGE is flexible enough to adapt to many TKG extrapolation models. Extensive experiments on four data sets demonstrate that OntoTKGE not only significantly improves the performance of many TKG extrapolation models but also surpasses many SOTA baseline methods.