Representational category
Interoperability
Re-use of existing vocabularies
For the calculation of this metric we need the vocabularies used in the KG. To recover this information we have used the same method that we have seen here. Then thanks to the REST API of the Linked Open Vocabularies (LOV), we check if the vocabularies is standard (i.e. is in the LOV). We assign at the metric 1 if no new vocabularies are defined, otherwise 0. Furthermore, track of the new vocabularies used will also be kept.
Re-use of existing terms
In this case we need all the terms used in the KG. We can get this information by using the following query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT DISTINCT ?o
WHERE {?s rdf:type ?o}
Then we search every term founded on the Linked Open Vocabularies, to check if is present or not (if yes this mean that is considered a standard term). At the end of the analysis of all the terms, we use the following formula to quantize the metric:
\[m_{newTerms} = 1.0 - \frac{numNewTerms}{totalTermsInTheKG}\]