Hi, would you please give a pointer to these discussions concerning adoption of the external ontologies? Kind regards, Aleksander Smywinski-Pohl ---- Wł. Pt, 09 sty 2015 20:10:31 +0100 Joe Filceolaire <filceolaire(a)gmail.com> napisał(a) ---- Till now our subclass of has developed organically from the bottom up. Their has been some discussion about adopting an existing upper level ontology but no decisions. In principle there is no reason why we can't incorporate all of these - after all the English Wikipedia category tree has three alternative high level ontologies! Part of will lead to universe where it is used to describe physical objects but I can imagine other ' part of' trees with root items such as science or religion. Joe On 9 Jan 2015 18:16, "Markus Krötzsch" <markus(a)semantic-mediawiki.org> wrote: I am not the one to decide this, but from my POV: (1) It would be nice to have a single, most general "root element". Using "Entity" as this root element could be sensible, with a suitable definition of "Entity" as anything we can refer to (i.e., any item). (2) Every entity should be an instance of this root element (or of one of its subclasses) (3) Every class should be a subclass of this root element (or of one of its subclasses). This is something that conceptually follows from (2), but not in a strict logical sense (open wrld assumption), so it makes sense to state it. In practice, there are many roots in the class hierarchy. Neither (2) nor (3) are currently true in the data. So better don't rely on this. Part-of has nothing to do with this. * Part-of does not mix with instance-of/subclass-of in natural ways. For example, it is *not* true that a part-of something that is an instance-of class C is also part-of C. There is just no immediate interaction between part-of on the one hand and subclass-of/instance-of on the other. * It is also not the case that everything needs to be directly or indirectly part of the root element. Part-of is one of the broadest relations used on Wikidata, and it has so many different meanings that it would be foolish to require them to converge to one thing. Every physical object is eventually part-of the universe, Q1, but Q1 is not part-of anything else in this same (physical) sense -- certainly not of Entity. * Part-of is transitive (if A part-of B and B part-of C then A part-of C), which makes it similar to subclass-of in this respect. Cheers, Markus On 09.01.2015 18:18, james(a)j1w.xyz wrote: I've noticed that many of the items in Wikidata have as their root item (via combinations of subclass-of, instance-of, and part-of relationships) the item named "entity" (Q35120). For example, the musical note named "E♭" is rooted at "entity" via various paths, including the following: E♭ (Q633464) instance-of note (Q263478) part-of musical notation (Q233861) part-of music (Q638) subclass-of art (Q735) subclass-of process (Q3249551) subclass-of event (Q1190554) subclass-of entity (Q35120) I have the following questions related to the example above: 1) Is the intent that all items in Wikidata have as their root item (via combinations of subclass-of, instance-of, and part-of relationships) the item named "entity" (Q35120)? 2) Is it the intent that any item (e.g. music) that is a subclass-of another item (e.g. art), have as its root item (via only subclass-of relationships) the item named "entity" (Q35120)? To summarize these questions as they apply to a project on which I'm working: Given a tree that has as its root the item named "entity" (Q35120), would/should it be possible to navigate from the root to every item (QXXXXXXX) in the Wikidata database? Regards, James Weaver _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l