I have removed the statement *"instance of* chemical compound" from ethanol (Q153) [1].
A few proposals have been made in this thread about how -- or whether -- to use *instance of* (i.e. rdf:type, P31) to classify 'ethanol' and other chemical compounds, but there seems to be consensus that "*instance of* chemical compound" is not the way to do it. Summary of proposals: 1. *Do not use instance of for chemical compounds*. Such statements make Wikidata incompatible with many major scientific ontologies, like ChEBI, Gene Ontology and Disease Ontology, which use *instance of* as defined in the Relation Ontology (RO) [2]. Note that RO defines instances as particular things that have a unique location in space and time, whereas classes are universal, general entities which have particular instances. Instances and classes are thus disjoint, so RO-based ontologies cannot have entities that have both *instance of* (rdf:type, P31) and *subclass of* (rdfs:subClassOf, P279) statements as is possible in OWL 2 DL via punning. 2. *Use statements like "instance of type of chemical compound" for chemical compounds*. Doing so makes it easier to generate lists of chemical compounds, and is valid in OWL 2 DL -- it is metamodeling via punning. Let's build consensus for how (or whether) we want to use *instance of* for chemical compounds before any mass edits to remove or replace the 14969 other "*instance of* chemical compound" claims [3] or adding statements like "*instance of *type of chemical compound" to ethanol. Micru has a different proposal for how to model items, which incidentally does not represent "ethanol" as an instance [4]. However, that proposal is clearly a more radical vision for Wikidata, and probably warrants a separate thread for discussion. Eric https://www.wikidata.org/wiki/User:Emw [1] Removal of "*instance of* chemical compound" from ethanol: https://www.wikidata.org/w/index.php?title=Q153&diff=162563849&oldid=162327014 [2] Barry Smith et al. (2005). *Relations in Biomedical Ontologies*. http://genomebiology.com/2005/6/5/r46 [3] All "*instance of* chemical compound" claims on Wikidata. http://tools.wmflabs.org/wikidata-todo/autolist.html?q=claim[31:11173] [4] "'ethanol' is no longer an instance, but a class". https://lists.wikimedia.org/pipermail/wikidata-l/2014-October/004691.html
_______________________________________________ Wikidata-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikidata-l
