How Grounded is Wikipedia? A Study on Structured Evidential Support and Retrieval
Abstract
Wikipedia is a critical resource for modern NLP, serving as a rich repository of up-to-date and citation-backed information on a wide variety of subjects. The reliability of Wikipedia -- its groundedness in its cited sources -- is vital to this purpose. This work analyzes both how grounded Wikipedia is and how readily fine-grained grounding evidence can be retrieved. To this end, we introduce PeopleProfiles -- a large-scale, multi-level dataset of claim support annotations on biographical Wikipedia articles. We show that: (1) ~22% of claims in Wikipedia lead sections are unsupported by the article body; (2) ~30% of claims in the article body are unsupported by their publicly accessible sources; and (3) real-world Wikipedia citation practices often differ from documented standards. Finally, we show that complex evidence retrieval remains a challenge -- even for recent reasoning rerankers.
Keywords
Cite
@article{arxiv.2506.12637,
title = {How Grounded is Wikipedia? A Study on Structured Evidential Support and Retrieval},
author = {William Walden and Kathryn Ricci and Miriam Wanner and Zhengping Jiang and Chandler May and Rongkun Zhou and Benjamin Van Durme},
journal= {arXiv preprint arXiv:2506.12637},
year = {2025}
}