Structured, linked, open data

How is data structured on Wikidata?

Every item of data on Wikidata represents a unique entity so is given a unique Q number to identify it.

Douglas Adams is Q42. Can you guess what Q13 is?

Within these item pages, information is stored in a series of statements.

A statement consists of claims which are made up of Properties and Values. Properties have a unique P number. The most important is P31 (instance of) as this is the all important ‘what is it?’ statement.

The Value can be another item of data on Wikidata so in this way links are built up between items on Wikidata.

Statements should be referenced so the information is verifiable. Adding the Reference URL (P854) is important so we can add in the provenance of where the data was sourced from.

Qualifiers may also be needed to ensure the information is accurate and true. e.g. Jane Belson was only Douglas Adams’ wife for a certain period of time so we need to add a qualifier on the dates for the statement about his spouse to be true.

Some example use cases

1. The GeneWiki project – queries. (video)

2. The collections of the National Library of Wales. – Histropedia timeline. (video)

3. Scholia – create on-the-fly scholarly profiles. (video)

4. The EveryPolitician project. (video).

5. The Sum of All paintings project – a WikiProject to get an item for every notable painting. Worklists.

6. Crotos – a search and display engine for visual artworks powered by Wikidata and Wikimedia Commons. 

7. Filter results on Crotos to only show images that have particular things depicted e.g. images with boats.

7. IIIF Cropper on Crotos.  – crop parts of images to show only what you are interested it is depicting. e.g. kisses

8. The WikiCite project – an initiative (and a series of events) aiming to build a bibliographic database in Wikidata to serve free knowledge. WikiProject Source MetaData is the place on Wikidata where coordination of these efforts happens.

9. The Zika Corpus (timeline).

10. MPs’ occupations and MPs’ place of education.


(Samuel Bough [Public domain], via Wikimedia Commons)