Class Order Disorder in Wikidata and First Fixes

TL;DR

This paper investigates class order violations in Wikidata, quantifies their prevalence through SPARQL queries, and evaluates the impact of manual corrections, proposing solutions for improved ontology consistency.

Contribution

It provides a systematic analysis of class order issues in Wikidata and suggests methods to address these problems through tooling and community involvement.

Findings

Significant class order violations identified in Wikidata

Manual fixes reduce some violations but do not eliminate all issues

Proposed tools and community efforts could improve ontology quality

Abstract

Wikidata has a large ontology with classes at several orders. The Wikidata ontology has long been known to have violations of class order and information related to class order that appears suspect. SPARQL queries were evaluated against Wikidata to determine the prevalence of several kinds of violations and suspect information and the results analyzed. Some changes were manually made to Wikidata to remove some of these results and the queries rerun, showing the effect of the changes. Suggestions are provided on how the problems uncovered might be addressed, either though better tooling or involvement of the Wikidata community.