Having worked at Metaweb/Google on Freebase, I'd be one of the first to admit that Freebase's types conflate too many concepts as they were both used for "Is A" class assertions and to group properties that were frequently edited together (in the UI) and for more contextual descriptions and for...
Over time, the class use was mostly abandoned for reasons like Paule's actor example.
I like the property-centric approach of wikidata, but is there a notion of subproperties for contextual refinement? I only found this:
https://www.wikidata.org/wiki/Property:P1647
-jason
On Thu Jan 08 2015 at 3:07:47 PM Paul Houle ontology2@gmail.com wrote:
There is the cultural factor here that Freebase took an approach which is very similar to the RDFS approach in that they like the idea of defining separate properties like
:HumanBirthDate :HorseBirthDate :DogBirthDate
You can then treat these as subproperties of :AnimalBirthDate which is in turn a subproperty of :StartDate, or something like that.
Freebase has a metaschema that does this sort of aggregation
https://developers.google.com/freebase/v1/search-metaschema
To a system designer who puts economy and simplicity first, there is something maddening about how Freebase defines separate types for "Film Actor", "TV Actor" and "Theatre Actor", since you might think an actor is just an actor and that the property to say an actor appeared in a film is almost the same as saying actor appeared in a TV episode; look deeper of course and you find different modelling needs. For instance there is a big difference between a TV actor with a recurring role and a TV actor who appears in one episode, etc.
I think Freebase approached it this way because they had the idea of it being divided into separate "bases" which can managed separately; this means you get vocabulary tuned to each domain rather than somebody figuring out the grand scheme ahead of time.
On Thu, Jan 8, 2015 at 4:52 PM, Peter F. Patel-Schneider < pfpschneider@gmail.com> wrote:
What then is P17 supposed to be used for?
Could, I, for example, use P17 on the address of the Swiss embassy in Germany and have Switzerland as the value?
"associated" is generally too weak a word to use in describing properties.
peter
On 01/08/2015 01:46 PM, Thad Guidry wrote:
Markus,
Devils in the details. =)
You used the English word "associated". That's great. Then I would propose to expand the definition of P17 just a bit to add that.
P17 Country - sovereign state of this item ... to ... sovereign state ASSOCIATED with this item
Then you save the world. =)
Thoughts ? Agreement ?
Secondly, the Description: (Description :colon: on the Discussion page https://www.wikidata.org/wiki/Property_talk:P17) is defining a Country... not the description of the Country __Property__..which is the line just above it. How is the Description :colon: line supposed to work or be really used for ? Seems like the Description :colon: line is basically describing the Represents :colon: line.... lol. Very confusing.
Thad +ThadGuidry https://www.google.com/+ThadGuidry
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