On mið 26.ágú 2015 23:05, James Heald wrote:
There are a *lot* of problems with P279 (subclass), right across Wikidata.
These will only be corrected once people start doing searches in a systematic way and addressing the anomalies they find.
In this case, politician (Q82955) should *not* be a subclass of human (Q5), instead it should be a subclass of something like occupation (Q13516667), or alternatively perhaps profession (Q28640).
My understanding is that currently there are a vast number of incorrect subclass relationships in the project, messing up tree searches, and so far it is something that has simply not yet been systematically addressed.
-- James.
For now, what's the best way to find (and perhaps correct) incorrect declarations like these?
If I were to just change items for commonly used items like politician (Q82955) it might be construed as vandalism or someone who doesn't care about or understand the Stubbs-declared-as-a-human problem might just add that declaration back later.
When it comes to the gender property (P21), the human readable description indicates that it's to define genders in general, yet it's declared as an instance of an item (Q18608871) which only applies to humans, which of course has consequences further up in the hierarchy since the maintainers of item Q18608871 faithfully assume it only applies to humans.
In the case of the hierarchy Stubbs is associated with the maintainers have assumed all mayors are, without exception, humans or they somehow thought that if there were exceptions to this, the machines could somehow detect and apply them in each case. Both of those methods are, I think we agree, are wrong and we should find out why it's happening.
Is there a tool where one can put in a Wikidata item and it extracts declarations based on "higher" properties like subclass or instance of? Like if I were to input the item for Stubbs, it would travel the hierarchy and tell me what would be assumed about Stubbs based on the declarations further up in the tree.
- Svavar Kjarrval