As I understand it, Freebase explicitly rejected inheritance through subclass relations. Therefore it has no class tree and indirect inheritance.  It is "flat".  Every item has to directly have all the values that pertain to it.  Is that right? 

Wikidata, on the other hand, follows OWL which uses subclasses to form a tree. Therefore, information is indirect and queries need to understand this.  If a Property is disambiguating, it can be an instance of an Item which is ultimately a subclass of https://www.wikidata.org/wiki/Q6545185 "unique identifier". In a system like Wikidata which allows inheritance, a query needs to follow the tree (unlike Freebase which is flat and you don't follow any inference). It is possible that a query engine can cache the result of such an indirect inference, but the raw database does not need to "flatten" everything like Freebase. Is that OK?

- Jeff

On 2015/01/09 16:30, Thad Guidry wrote:
So Lydia,

Your saying that if I see https://www.wikidata.org/wiki/Q18614948 as a property on another Property... then that is similar to the Freebase "disambiguating" flag ?

In Freebase, we have just one flag.... but that is not the case here, correct ?  Wikidata has (or might have) several such "disambiguating" flags via the property on Property ?

It would be nice, from an API and developer perspective, to not have to discover all those disambiguating properties....but have only a master disambiguating property to work with...a single "disambiguator" flag, just like Freebase has.... is this possible, where someone can go through an mark all of them as "disambiguating" ?

My hope is that the Wikidata query service could give me nicely formatted output for claims that only contain disambiguating property data.... just like the Freebase API example URL that I mentioned at the beginning of the thread.  So hopefuly you guys are saying that is possible via the property on a Property.





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