SMW and Wikidata

About Wikidata
The goal of Wikidata is to create a common data repository (something similar to Wikimedia Commons) where data can be shared among other Wikimedia projects and by/with third parties.

Differences between SMW and Wikidata


The main use case of Wikidata (a centralised, multi-lingual site that serves as a data repository) is different from that of SMW (a data-enhanced MediaWiki), and this leads to a number of differences.

Central to a wikidata statement is that its factual claim is supported by reference(s) (source of the claim). For example, when SMW makes a claim about the population of Berlin it would only be annotated with Berlin has a population of 3,5 Mio (see Figure 1) where Wikidata would make an extended statement describing it as Berlin's population being 3,5 Mio as of 2011 according to the German statistical office (see Figure 2).

In summary

 * Every fact will also have an (optional) reference
 * Wikidata will also use more complex datatypes (e.g., since many text values can be translated).
 * Both Wikidata and SMW are still mostly based on property-value assignments, and Wikidata will have a Property namespace.
 * Complex structures in Wikidata could be captured in SMW using internal objects

Integration between SMW and Wikidata
For a first example, see Service links and the page for Vienna with the Property:Wikidata ID. It demonstrates, how Service links or External identifiers can be used to link values of a SMW property to Wikidata IDs.

Technical background
The software underlying Wikidata is called Wikibase. It consists of two extensions: Repository (where data is stored; this will run at wikidata.org) and Client (that pulls data into other MediaWiki sites; this will run at wikipedia.org). Both extensions will be installable on MediaWiki sites to get Wikidata-like features there.

The user interface of Wikibase Repository will be based on input forms, a bit like a full-page, editable Factbox, but much more advanced, with a lot of support for entering values.

Ideas for a integration of SMW nad Wikibase/Wikidata

 * Push data from SMW to a Wikibase instance (as it would be done wich any other triple store)
 * Push data from SMW to Wikidata.
 * Import ontolgies from Wikidata to SMW instances