Uncertainty and debate in statements describing Wikidata Works of art

This dataset comprises a selection of statements from all artworks in Wikidata. 

In particular, 

• natures.json stores statements with a “Nature of statements” qualifier. Statements, independently of rank, can be decorated with an additional triple using predicate P5102. 54 terms among 283 available may mark the statement as uncertain or debated (e.g. debated, hypothesis, possibly). For example, the painting “Abstract Speed + Sound” (Q19882431) by Giacomo Balla is deemed to be possibly part of a triptych.  
• non-asserted.json contains those statements which are not asserted. Competing statements are represented via a ranking mechanism (e.g., Preferred, Normal and Deprecated). Individual statements are not actually asserted, but an extra triple is added those that are deemed true. For example, the painting “Madonna with the Blue Diadem” (Q738038) has been attributed to Raphael (non asserted statement, ranked as normal) and Gianfrancesco Penni (asserted statement, ranked as preferred and additionally asserted). 
• null-valued.json contains all statements with a null-valued objects. A statement can be associated with a blank node. This is meant to imply that the statement is associated with an unknown value, rather than a missing statement. For example, “Missal for the use of the ecclesiastics of Clermont' (Q113302686), an illuminated manuscript from the 14th century, has been recorded with both an unknown creator and author.
• sourcing-circumstances.json  stores statements with a “Sourcing circumstance” qualifier. As for Natures of statements only statements with an uncertain qualifier have been selected.