On 17.08.2016 01:43, Benjamin Good wrote:
I am about to propose much more widespread use of Property:P2888 "exact match" for linking from a wikidata item to a URI that should resolve to linked data about the same concept from another semantic web resource. (amongst the biomedical items that our team works with)
Is there any other pattern that the community here is using to do this that we should be following?
As Gerard said, "exact" correspondence might be difficult in most cases, but something slightly weaker should be ok. Something that one should note is that, even in cases where two things are about the same "idea", their usage in RDF is usually different if you compare Wikidata RDF to external RDF. For example, a class in an external RDF document might have instances assigned via rdf:type whereas a class-like item in Wikidata has instances assigned via a chain of properties
http://www.wikidata.org/prop/P31 and http://www.wikidata.org/prop/statement/P31
possibly with further quantifiers assigned to the middle element. So you cannot get a simple, direct correspondence on a structural level anyway.
Nonetheless, the community uses, e.g., equivalent property (P1628) statements to link Wikdiata properties to external RDF properties. The intended meaning of this is apparently not fully formal, since each Wikidata property corresponds to many RDF properties in the Wikidata RDF exports. Rather, this seems to be an informal hint for consumers that want to implement a proper mapping (e.g., by specifying an ontology or a SPARQL query that translates the Wikidata RDF structure into external RDF structures). Any such mapping will require additional design decisions, since you have to do something with the Wikidata qualifiers (which don't have a place if you map a complex Wikidata statement to a simple triple).
There are also properties "equivalent class" (P1709), "external superproperty" (P2235), and "external subproperty" (P2236). See
https://tools.wmflabs.org/sqid/#/browse?type=properties&datatypes=5:Url
for the list of all 34 URL-type properties. Maybe you can discover others that are relevant for you.
Best regards,
Markus
thanks Ben
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