Structural Quality Metrics to Evaluate Knowledge Graphs
This work addresses the need for better quality assessment in knowledge graphs for researchers and practitioners, though it is incremental as it builds on existing structural analysis concepts.
The authors tackled the problem of evaluating knowledge graph quality by proposing six structural metrics and applying them to analyze five major web knowledge graphs and one integrated knowledge graph, revealing characteristics not captured by scale-related indicators like class and property counts.
This work presents six structural quality metrics that can measure the quality of knowledge graphs and analyzes five cross-domain knowledge graphs on the web (Wikidata, DBpedia, YAGO, Google Knowledge Graph, Freebase) as well as 'Raftel', Naver's integrated knowledge graph. The 'Good Knowledge Graph' should define detailed classes and properties in its ontology so that knowledge in the real world can be expressed abundantly. Also, instances and RDF triples should use the classes and properties actively. Therefore, we tried to examine the internal quality of knowledge graphs numerically by focusing on the structure of the ontology, which is the schema of knowledge graphs, and the degree of use thereof. As a result of the analysis, it was possible to find the characteristics of a knowledge graph that could not be known only by scale-related indicators such as the number of classes and properties.