Our goal is to settle on a scale of "Item quality" that is similar to Wikipedia's notion of article quality from https://en.wikipedia.org/wiki/Wikipedia:Version_1.0_Editorial_Team/Assessment
Draft: https://www.wikidata.org/wiki/Wikidata:Item_quality
Discussion: https://www.wikidata.org/wiki/Wikidata_talk:Item_quality
Past discussion on Project_chat: https://www.wikidata.org/w/index.php?title=Wikidata:Project_chat&oldid=443491016#Quality_Criteria_for_Building_a_Tool_to_Evaluate_Item_Quality