There is a proposal for some kind of class disjointness : https://www.wikidata.org/wiki/Wikidata:Property_proposal/Generic#subclass this is here for a while now, maybe a few more supporters would speed up the process :)
I think a proposal for "DisjointWith" was rejected a long time ago. But another one could pass. 2015-11-10 13:27 GMT+01:00 Markus Krötzsch <mar...@semantic-mediawiki.org>: > On 29.10.2015 05:41, Benjamin Good wrote: > >> For what its worth, I tend to agree with Peter here. It makes sense to >> me to add constraints akin to 'disjoint with' at the class level. >> > > +1 for having this. This does not preclude to have an additional mechanism > on the instance level if needed to augment the main thing, but the classes > are an easier way to start. > > This can also help with detecting other issues that are unrelated to > merging. For instance, nothing should be an event and an airplane at the > same time. > > We need a common approach on how to deal with ambiguous Wikipedia > articles. One option would be to create an "auxiliary" item that is not > linked to Wikipedia in such a case, but that is used to represent some > aspects of the "main" item that would otherwise be incompatible. > > Benjamin is right that these issues are not specific to the bio domain. > It's rather the opposite: the bio domain is one of the domains that is > advanced enough to notice these problems ... > > The >> problem I see is that we don't exactly have classes here as the term is >> used elsewhere. I guess in wikidata, a 'class' is any entity that >> happens to be used in a subclassOf claim ? >> > > In this case, one can leave this to the user: two items that are specified > to be disjoint classes are classes. > > In the Wikidata Taxonomy Browser, we consider items as classes if one of > the following is true: > (1) they have a "subclass of" statement > (2) they are the target of a "subclass of" statement > (3) they are the target of an "instance of" statement > > We then (mostly) ignore the classes that do not have own instances or own > subclasses (the "leafs" in the taxonomy), since these are very many: > * The above criterion leads to over 200,000 class items. > * Only about 20,000 of them have instances or subclasses. > > >> Another way forward could be to do this using properties rather than >> classes. I think this could allow use to use the constraint-checking >> infrastructure that is already in place? You could add a constraint on >> a property that it is 'incompatible with' another property. In the >> protein/gene case we could pragmatically use Property:P351 (entrez gene >> id), incompatible with Property:P352 (uniprot gene id). More >> semantically, we could use 'encoded by' incompatible-with 'encodes' or >> 'genomic start' >> > > I think the constraint checking infrastructure should be able to handle > both approaches equally well. If "disjoint with" is a statement, one could > even check this constraint in SPARQL (possibly further restricting to query > only for constraint violations in a particular domain). > > Cheers, > > Markus > > >> On Wed, Oct 28, 2015 at 5:08 PM, Peter F. Patel-Schneider >> > > _______________________________________________ > Wikidata mailing list > Wikidata@lists.wikimedia.org > https://lists.wikimedia.org/mailman/listinfo/wikidata >
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