Wikidata

Wikidata (.org) is a knowledge base, an effort to store and serve structured data to Wikimedia wikis and to a more limited extent to other parties. Wikidata effort saw the daylight in 2012.

The underlying software is the Wikibase which consists of 2 Mediawiki extensions, the repository extension and the client extension.

Wikibase allows interwiki links to be managed with Wikidata removing much contributor annoyanges, redundancy and error-proneness.

Wikidata is obviously a main source of reference level data once it is technically possible for non-WMF wikis to access the data items.

It can be accessed outside of WMF wikis with with

• Wikidata advice on how to query Wikidata's endpoint using SPARQL.
• mw:Wikidata Toolkit is a way for Java programs to access data in the Wikidata repository.
• SPARQL Endpoint interface to Python
• Wikidata offers its database for download

Main entry point of any Wikidata item is a JSON dictionary, that has this form:

{“labels”: by-language dictionary

“descriptions”: by-language dictionary

“aliases”: by-language dictionary

“claims”: list of property and values

“sitelinks”: by-language dictionary}

Useful information

• Wikidata's list of external tools that make use of Wikidata's knowledge

More info

• Metawiki on Wikidata
• Wikipedia advice on Wikidata issues

See also

• Database for a higher level view of what is going on with the databases
• Semantic MediaWiki is system for inputting and querying semantic data within the MediaWiki and it is implemented as extension(s).
• DBpedia the original structured data harvesting effort for the MediaWiki wikis