Key differences between Properties and Items: * Properties have a data type, items don't. * Items have sitelinks, Properties don't. * Items have Statements, Properties will support Claims (without sources).
The software needs these constraints/guarantees to be able to take shortcuts, provide specialized UI and API functionality, etc. Yes, it would be possible to use items as properties instead of having a separate entity type. But they are structurally and functionally different, so it makes sense to have a strict separate. This makes a lot of things easier, e.g.: * setting different permissions for properties * mapping to rdf vocabularies More fundamentally, they are semantically different: an item describes a concept in "the real world", while a property is a structural component used for such a description. Yes, properies are simmilar to data items, and in some cases, there may be an item representing the same concept that is represented by a property entity. I don't see why that is a problem, while I can see a lot of confusion arising from mixing them. -- daniel Am 28.05.2014 09:25, schrieb David Cuenca: > Since the very beginning I have kept myself busy with properties, thinking > about > which ones fit, which ones are missing to better describe reality, how > integrate > into the ones that we have. The thing is that the more I work with them, the > less difference I see with normal items.... and if soon there will be > statements > allowed in property pages, the difference will blur even more. > I can understand that from the software development point of view it might > make > sense to have a clear difference. Or for the community to get a deeper > understanding of the underlying concepts represented by words. > > But semantically I see no difference between: > cement (Q45190) <emissivity (P1295)> 0.54 > and > cement (Q45190) <emissivity (Q899670)> 0.54 > > Am I missing something here? Are properties really needed or are we adding > unnecessary artificial constraints? > > Cheers, > Micru > > > _______________________________________________ > Wikidata-l mailing list > Wikidata-l@lists.wikimedia.org > https://lists.wikimedia.org/mailman/listinfo/wikidata-l > -- Daniel Kinzler Senior Software Developer Wikimedia Deutschland Gesellschaft zur Förderung Freien Wissens e.V. _______________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
