Hi all,
why are both the subclass of and instance of properties set for the ethanol
(showcase) item?
For me ethanol is a single concrete alcohol and it is not a class. There is
only one ethanol, with a single chemical formula and structure, so only the
instance of property is right for this
Based on the CHEBI ontology perspective, alcohol is a class with subclasses
like 'aromatic alcohol' which has subclasses like 'benzyl alcohols' which
has subclasses like 'methylbenzyl alcohol' and so on.
These relationships seem worth capturing and subclass seems like a
reasonable way to do it.
Hi, this is a long discussion :) Is is allowed by OWL2 notion called
Punning.
The rationale is that Hydrogen is a chemical elements, and that the
chemical element is not a subclass of atom. Rather a chemical elements is a
type of atom, so chemical elements is a metaclass : a class of class of
I Drafted an (unfinished) essay about classification on Wikidata including
metamodeling here : https://www.wikidata.org/wiki/Help:Item_classification
Metamodeling seems to me (and has proven to be) convenient in Wikidata.
Think that there is a lot of classes, and that regrouping classes with some
This is about chemical compounds, molecules. Here it's about atoms, I
think. Correct me if I have wrong information, but afaik CheBi has no
chemical elements class, so there is no real answer to the original
question.
But yes, those classes if they are not already on Wikidata seems OK to
have,
Am 25.09.2014 19:52, schrieb Alain Cuvillier:
Hi all,
why are both the /subclass of/ and /instance of/ properties set for the
ethanol
(showcase) item?
For me ethanol is a single concrete alcohol and it is not a class. There is
only
one ethanol, with a single chemical formula and
Oh, It was written ethanol and I read hydrogen my bad /o\
Anyway, metaclasses are a way to solve this kind of paradoxes.
Lets say we got a class alcohol types.
This class would have, amongst its instances, the ethanol class.
But a basic principle of ontologies (philosophically) is the
Hi,
I fully agree with Thomas and the other replies given here. Let me give
some other views on these topics (partly overlapping with what was said
before). It's important to understand these things to get the subclass
of/instance of thing right -- and it would be extremely useful if we
Fully agree with Markus' beautifully written explanation, although I am not
completely convinced of the level theory - but it seems to work in the
given examples, and a few other examples I was thinking through.
Note that Porsche 356 could very much be an instance of car model - but
not of car.
