"David Cuenca" dacuetu@gmail.com writes:
Jane, this info is in Wikipedia. For instance see: https://en.wikipedia.org/wiki/Waltzes_(Chopin)
N. 17 was attributed to Chopin (Kobylańska and others), Chomiński says that claim is spurious. And that is just one of many examples. According to Wikidata principles we should collect both statements and let the reader decide which source to believe. I can enter Kobylańska's claim, but I have no way to enter Chomiński's counter-claim.
I think it is important to be able to model that information because that is how sources act, they don't limit themselves to make "certain" claims, they also make "uncertain" claims or counter other claims (even if they don't offer better ones).
Since attributions in arts, history, composition and many other field are uncertain, doubtful, questioned, or contradicted without an alternative at significant rates - in the 10% magnitude if you go back in time a bit - we ought to have them.
Contradictions are indeed a new type of statement, because they have to refer to the staements they disclaim.
Purodha