Knowledge Graph Multilevel Abstraction: A Property Graph Reification Based Approach

Adding knowledge to data or information is an essential step for new information system, which need to break down silos in order to support a large diversity of applications. Conventional integration approaches have difficulties in meeting the flexibility required by new needs, mainly because they rely on rigid schema. Graph-based approaches, such as knowledge graphs, are promising, as they allow to use different graph models such as RDF or property graph models. However, they do not make it easy to describe complex relationships at different levels of abstraction. The reification process, already well-studied for RDF, is a promising solution to add new representation capabilities. This paper delves into the process of knowledge reification within the property graph model as a novel approach to enhance the expressivity of knowledge graph model by adding capabilities of representing complex relationships and multilevel abstractions. Based on the study of reification models for RDF, we formalize a new model for property graphs by generalizing the different reification techniques.