“…Existing evaluation metrics used in related fields such as snippet generation for ontologies [28] and documents [16] are mainly based on a human-created ground truth. However, an RDF dataset may contain millions of RDF triples, e.g., when it wrapped from a large database [23,18,19,33], or streaming data [25,24], or comes from a manufacturing environment [37,22,26] being much larger than an ontology schema or a document. It would be difficult, if not impossible, to manually identify the optimum snippet as the ground truth.…”