Versatility

  1. Usage of multiple languages
  2. Different serialization formats
  3. Accessing of data in different ways

Usage of multiple languages

To check if there are different languages supported (and this is indicated), we use the following query:

SELECT DISTINCT ?triples
WHERE{
?s ?p ?o.
BIND(LANG(?o) as ?triples)
}

To quantize this metric, we assign 1 if we have indication about the languages used, 0 otherwise.

Different serialization formats

We calculate this metric bby using two different methods: the first is to look for triples with void:feature predicate within the VoID file, the second one involves executing the following query on the SPARQL endpoint:

PREFIX void: <http://rdfs.org/ns/void#>
PREFIX dcat: <http://www.w3.org/ns/dcat#>
SELECT DISTINCT ?o
WHERE{
{?s void:feature ?o}
UNION
{?s dcat:mediaType ?o}
}

To quantize this metric, we assign 1 if we have indication about the serialization formats available, 0 otherwise. —

Accessing of data in different ways

In this metric we insert the available links to access the KG, only if this links are online. To recover the links to access the KG, we use the metadata returned by DataHub and LODCloud, and if we have a working SPARQL endpoint we also run the following query to get them:

PREFIX dcat: <http://www.w3.org/ns/dcat#>
SELECT DISTINCT ?o
WHERE {?s dcat:downloadURL ?o.}

The metric is then quantized by giving value 1 in the case we can access at the KG both throught the SPARQL endpoint or by downloading the RDF dump.