Wikidata Policies: How Shared Facts Keep Wikipedia Accurate and Connected

When you read a Wikipedia article about the population of Tokyo or the release date of a movie, you’re often seeing data pulled from Wikidata, a free, open knowledge base that stores structured facts used by all Wikipedia language editions. Also known as the central repository for Wikipedia’s structured data, it’s the backbone that keeps facts like birth dates, geographic coordinates, and scientific classifications consistent across 300+ language versions. Without Wikidata policies, every editor would have to retype the same numbers and dates over and over—leading to errors, contradictions, and wasted effort.

Wikidata policies aren’t about controlling content—they’re about making sure content works reliably. For example, if someone updates the population of Lagos in Wikidata, that change automatically shows up on English, Spanish, Swahili, and dozens of other Wikipedia pages. That’s possible because of strict rules around source verification, the requirement that every fact in Wikidata must be tied to a reliable, published reference. You can’t just add "I think it’s 15 million"—you need a government census, a peer-reviewed study, or a trusted news outlet. This is why Wikidata is more accurate than most commercial databases: every edit is open for review, and every source is public.

These policies also protect against bias. If a company tries to inflate its revenue numbers in Wikidata, the system flags it. If someone adds a disputed political claim without solid sourcing, it gets reverted. And because Wikidata is built as a knowledge graph, a network of interconnected facts where entities like people, places, and events link to each other, it can catch inconsistencies across topics. For instance, if a person’s birthplace is listed as Paris in one entry and Berlin in another, the system alerts editors. This isn’t magic—it’s policy-driven structure.

These rules aren’t just for experts. Anyone can help. You don’t need to edit Wikipedia to improve Wikidata. You can find missing data in a book, verify a date on a museum website, or fix a typo in a government report—all while following the same simple guidelines. The Wikimedia Foundation, the nonprofit that supports Wikipedia and its sister projects backs these policies with tools, training, and community moderation to keep things running smoothly.

What you’ll find in the articles below isn’t just a list of technical rules. It’s a look at how real people use Wikidata policies to fix misinformation, connect cultures, and make knowledge work across languages and borders. From how editors handle conflicting data during global events, to how small language communities rely on Wikidata to stay visible, these stories show why structured facts matter more than ever.