Question about this property : can it be applied to a non transitive property ?
We could have two « friend of » properties, one transitive, « the friend of my friend is mine », one not. If I then say, « what belongs to me belong to my friend » * in the transitive version it belongs also to the friend of my friend * can it be applied to the non transitive friendship ? This could mean that it just belongs to the friends with explicit statement I guess. I agree that « if A is an instance of B » and « B is a subclass of C » then « A is an instance of C » getting something weird as a result is a powerful tool to find consistency issues in the ontology. The « Classification » gadget takes advantage of this, cf. https://www.wikidata.org/wiki/Special:MyLanguage/Wikidata:Tools/Enhance_user_interface#Classification.js It shows a few classes in the class hierarchy an items belongs to and this item is supposed to be an instance of. If « Albert Einstein is a taxon » seems weird, the user can click to report a bug in the ontology on the ontology project talk page. Le dim. 22 mai 2022 à 17:42, Thad Guidry <[email protected]> a écrit : > Hi Thomas, > > Yes, your example is the kind of use case. And disagreements often come > up with the "then C is a part of B". > > And I've found that many times the classification problems where "wait a > second, this is not actually quite true, and the right class in the > hierarchy I'm thinking of" ... will typically be resolved, and > consensus more easily agreed by all parties when the class is either: > A. made more abstract for the benefit of all, but saving that... > B. make a new class, more broader, and less disagreeable by all parties > > It's just a simple data modeling problem oftentimes, but where "transitive > over" seems to expose them. > I see it more about getting consensus and the "it depends" seemed > oftentimes easily solved with a different broader class used or created and > applied. > > Thad > https://www.linkedin.com/in/thadguidry/ > https://calendly.com/thadguidry/ > > > On Sun, May 22, 2022 at 8:25 AM Thomas Douillard < > [email protected]> wrote: > >> Sounds not uninteresting, but without the context of the discussion it’s >> hard to understand what the problem actually is. Could include more details >> ? >> >> I googled a bit and found that a « transitive over » usecase could be >> If >> * researcher Livingstone « explores » Egypt >> * Egypt is a part of Africa >> then we can conclude that researcher livingstone explores Africa >> >> This would mean that the « explore » property would be transitive over « >> part of ». >> An example of this could be of course « instance of » who is of course >> transitive over « subclass of ». >> >> Yet « subclass of » is of course a transitive property by itself. If all >> mammals are animals (so ''mammal subclass of animal')' and all animals are >> organism ''animal subclass of living organism'', then of course all mammals >> are living organisms. >> >> As for transitivity of « part of » of course if A is a part of B and C is >> a part of A, then C is a part of B. The thing is that someone that studies, >> say a lineage of cell of some kind of animal could not necessarily >> considering to study the animal itself, so « studies » could not be >> considered to be transitive over « part of ». >> >> What exact reasoning problem do you have in mind ? >> >> Le sam. 21 mai 2022 à 17:56, Thad Guidry <[email protected]> a écrit : >> >>> I wanted to share my reply to a recent Telegraph conversation: >>> >>> Thad Guidry, [5/21/2022 10:22 AM] >>> [In reply to Nikki] >>> Agree somewhat, however in the case of P31 we already have P6609 that >>> describes the general SKOS/OWL "transitive over" and we added the >>> value-type constraint https://www.wikidata.org/wiki/Q21510865 to be >>> transitive property https://www.wikidata.org/wiki/Q18647515 >>> >>> But that was not the case with P279 ... where instead we stated that >>> P279 itself is an instance of transitive property ... which is what >>> probably confuses folks. >>> >>> [[wikilinksbot]], [5/21/2022 10:22 AM] >>> P31 (https://www.wikidata.org/entity/P31) – instance of >>> P6609 (https://www.wikidata.org/entity/P6609) – value hierarchy property >>> P279 (https://www.wikidata.org/entity/P279) – subclass of >>> >>> Thad Guidry, [5/21/2022 10:26 AM] >>> So P279 is a https://www.wikidata.org/wiki/Q18647515 and P31 is not. >>> >>> [[wikilinksbot]], [5/21/2022 10:26 AM] >>> P279 (https://www.wikidata.org/entity/P279) – subclass of >>> P31 (https://www.wikidata.org/entity/P31) – instance of >>> >>> Thad Guidry, [5/21/2022 10:29 AM] >>> Details here: https://www.w3.org/TR/owl-ref/#TransitiveProperty-def >>> >>> Thad Guidry, [5/21/2022 10:38 AM] >>> So... (lolol) .... through transitivity once an item becomes an instance >>> of a class... then it automatically inherits all properties of that >>> class... but only and strong ONLY WHEN it is considered an instance of a >>> class... and not before. >>> >>> Reasoners, interpreters (external, custom code, institutions, etc.) >>> might apply transitivity "slightly" differently for different contexts, and >>> might bucket some items prematurely to be considered an instance of a class >>> ... but generally, the old adage is that of the above paragraph... only >>> once it is considered an instance of. >>> >>> The problem as often seen in Wikidata is that sometimes higher classes >>> are currently not abstract enough sometimes to fulfill broader roles... *and >>> hence... a broader higher class oftentimes just needs to be created to make >>> things in the hierarchy a bit more sensical.* >>> >>> Thad >>> https://www.linkedin.com/in/thadguidry/ >>> https://calendly.com/thadguidry/ >>> _______________________________________________ >>> Wikidata mailing list -- [email protected] >>> To unsubscribe send an email to [email protected] >>> >> _______________________________________________ >> Wikidata mailing list -- [email protected] >> To unsubscribe send an email to [email protected] >> > _______________________________________________ > Wikidata mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
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