On mið 26.ágú 2015 13:58, Peter F. Patel-Schneider wrote:
I don't think that P21 (https://www.wikidata.org/wiki/Property:P21, sex or gender) is a subclass of P31 (https://www.wikidata.org/wiki/Property:P31, instance of). Properties aren't subclasses in general.
Perhaps you meant to talk about https://www.wikidata.org/wiki/Property:P21 (sex or gender) being related via (https://www.wikidata.org/wiki/Property:P31 (instance of) to https://www.wikidata.org/wiki/Q18608871 (Wikidata property for items about people). This indicates that the property should only be used on people, even though the description of the property itself talks about its use on animals.
It appears that Wikidata is not very consistent internally.
peter
Sorry, I'm not used to the Wikidata lingo.
To further explain my point (to which I think you have already agreed to): If I were to produce a code which makes assumptions based on such relations, the code would come to the contradiction that a non-human with a P21 relation is a human, if it were to recursively travel via in the hierarchy of declarations. P21 is declared with a P31->Q18608871 and Q18608871 is in turn declared P1269->Q5. Unless special precautions would be taken, anyone trying to generate an exhaustive list of all humans on Wikidata (without relying solely on the direct declaration on each item), they might find themselves with non-humans on that list due to travelling backwards via such relations.
In essence, it seems like P21 either wrongfully allows definitions of genders of non-humans or that the property is too broad for a declaration of P31->Q18608871.
- Svavar Kjarrval