Wikidata

Last updated
Wikidata
Wikidata-logo-en.svg
Wikidata main page (2019).png
Main page of Wikidata
Type of site
Available inmultiple languages, Wikidatan
Founded29 October 2012;7 years ago (2012-10-29)
Owner Wikimedia Foundation [1] [2]
Created byWikidata editors
Website www.wikidata.org OOjs UI icon edit-ltr-progressive.svg
Alexa rankDecrease Positive.svg 7,818 (January 2020) [3]
CommercialNo
RegistrationOptional

Wikidata is a collaboratively edited knowledge base hosted by the Wikimedia Foundation. It is a common source of open data that Wikimedia projects such as Wikipedia can use, [4] [5] and anyone else, under a public domain license. This is similar to the way Wikimedia Commons provides storage for media files and access to those files for all Wikimedia projects, and which are also freely available for reuse. Wikidata is powered by the software Wikibase. [6]

Contents

Concepts

Screenshots
Wikidata statements Mars.png
Three statements from Wikidata's item on the planet Mars. Values include links to other items and to Wikimedia Commons.
Wikidata layout Phase I.png
A layout of the four main components of a phase-1 Wikidata page: the label, description, aliases and interlanguage links.
Interlanguage links prior to Wikidata.png
A Wikipedia article's list of interlanguage links as they appeared in an edit box (left) and on the article's page (right) prior to Wikidata. Each link in these lists is to an article that requires its own list of interlanguage links to the other articles; this is the information centralized by Wikidata.
Interlanguage links provided by WikiData.png
The "Edit links" link takes the reader to Wikidata to edit interlanguage links.

Items

Wikidata is a document-oriented database, focused on items, which represent topics, concepts, or objects. Examples of items include 1988 Summer Olympics (Q8470), love (Q316), Elvis Presley (Q303), and Gorilla (Q36611). Each item is identified by a unique number, prefixed with the letter Q, known as a "QID". This enables the basic information required to identify the topic the item covers to be translated without favouring any language.

Item labels need not be unique. For example, there are two items named "Elvis Presley": Elvis Presley (Q303) represents the American singer and actor, and Elvis Presley (Q610926) represents his self-titled album. But the label and the description text needs to be unique together.

Fundamentally, an item consists of a label, a description, optionally multiple aliases, and some number of statements.

This diagram shows the most important terms used in Wikidata Datamodel in Wikidata.svg
This diagram shows the most important terms used in Wikidata

Property

Example of a simple statement consisting of one property-value pair Simple statement - Earth.png
Example of a simple statement consisting of one property-value pair

A property describes the data value of a statement and can be thought of as a category of data, for example color (P462) for the data value blue (Q1088). Properties, when paired with values, form a statement in Wikidata. Properties are also used in qualifiers. The most used property is instance of (P31), that is used on more than 53,000,000 item pages. [7]

Properties have their own pages on Wikidata and are connected to items, resulting in a linked data structure.

Statements

Statements are how any information known about an item is recorded in Wikidata. Formally, they consist of key-value pairs, which match a property (such as "author", or "publication date") with one or more values (such as "Sir Arthur Conan Doyle" or "1902"). For example, the informal English statement "milk is white" would be encoded by a statement pairing the property color (P462) with the value white (Q23444) under the item milk (Q8495).

Statements may map a property to more than one value. For example, the "occupation" property for Marie Curie could be linked with the values "physicist" and "chemist", to reflect the fact that she engaged in both occupations. [8]

Values may take on many types including other Wikidata items, strings, numbers, or media files. Properties prescribe what types of values they may be paired with. For example, the property official website (P856) may only be paired with values of type "URL". [9] Properties may also define more complex rules about their intended usage, termed constraints. For example, the capital (P36) property includes a "single value constraint", reflecting the reality that (typically) territories have only one capital city. Constraints are treated as hints rather than inviolable rules. [10]

Optionally, qualifiers can be used to refine the meaning of a statement by providing additional information that applies to the scope of the statement. For example, the property "population" could be modified with a qualifier such as "as of 2011". Statements may also be annotated with references, pointing to a source backing up the statement's content. [11]

Lexemes

In linguistics, a lexeme is a unit of lexical meaning. Similarly, Wikidata's lexemes are items with a structure that makes them more suitable to store lexicographical data. Besides storing the language to which the lexeme refers, they have a section for forms and a section for senses. [12]

Wikidata Birthday Celebration at Kerala

Development history

The creation of the project was funded by donations from the Allen Institute for Artificial Intelligence, the Gordon and Betty Moore Foundation, and Google, Inc., totaling 1.3 million. [13] [14] The development of the project is mainly driven by Wikimedia Deutschland and was originally split into three phases: [15]

  1. Centralising interlanguage links – links between Wikipedia articles about the same topic in different languages
  2. Providing a central place for infobox data for all Wikipedias
  3. Creating and updating list articles based on data in Wikidata

Initial rollout

Wikidata was launched on 29 October 2012 and was the first new project of the Wikimedia Foundation since 2006. [4] [16] [17] At this time, only the centralization of language links was available. This enabled items to be created and filled with basic information: a label – a name or title, aliases – alternative terms for the label, a description, and links to articles about the topic in all the various language editions of Wikipedia.

Historically, a Wikipedia article would include a list of interlanguage links, being links to articles on the same topic in other editions of Wikipedia, if they existed. Initially, Wikidata was a self-contained repository of interlanguage links. Wikipedia language editions were still not able to access Wikidata, so they needed to continue to maintain their own lists of interlanguage links.

On 14 January 2013, the Hungarian Wikipedia became the first to enable the provision of interlanguage links via Wikidata. [18] This functionality was extended to the Hebrew and Italian Wikipedias on 30 January, to the English Wikipedia on 13 February and to all other Wikipedias on 6 March. [19] [20] [21] [22] After no consensus was reached over a proposal to restrict the removal of language links from the English Wikipedia, [23] the power to delete them from the English Wikipedia was granted to automatic editors (bots). On 23 September 2013, interlanguage links went live on Wikimedia Commons. [24]

Statements and data access

On 4 February 2013, statements were introduced to Wikidata entries. The possible values for properties were initially limited to two data types (items and images on Wikimedia Commons), with more data types (such as coordinates and dates) to follow later. The first new type, string, was deployed on 6 March. [25]

The ability for the various language editions of Wikipedia to access data from Wikidata was rolled out progressively between 27 March and 25 April 2013. [26] [27]

On 16 September 2015, Wikidata began allowing so-called arbitrary access, or access from a given Wikidata item to the properties of items not directly connected to it. For example, it became possible to read data about Germany from the Berlin article, which was not feasible before. [28] On 27 April 2016 arbitrary access was activated on Wikimedia Commons. [29]

Query service

On 7 September 2015, the Wikimedia Foundation announced the release of the Wikidata Query Service, [30] which lets users run queries on the data contained in Wikidata. [31] The service uses SPARQL as the query language. As of November 2018, there are at least 26 different tools that allow to query the data in different ways. [32]

Reception

In November 2014, Wikidata received the Open Data Publisher Award from the Open Data Institute “for sheer scale, and built-in openness”. [33]

As of November 2018, Wikidata information is used in 58.4% of all English Wikipedia articles, mostly for external identifiers or coordinate locations. In aggregate, data from Wikidata is shown in 64% of all Wikipedias' pages, 93% of all Wikivoyage articles, 34% of all Wikiquotes', 32% of all Wikisources', and 27% of Wikimedia Commons'. Usage in other Wikimedia Foundation projects is testimonial. [34]

As of November 2018, Wikidata's data is visualized by at least 20 other external tools [35] and at least 100 papers have been published about Wikidata. [36] Its importance has been recognized by numerous cultural institutions. [37]

The bars on the logo contain the word "WIKI" encoded in Morse code. [38]

Applications

See also

Related Research Articles

History of Wikipedia Historical development of Wikipedia

Wikipedia began with its first edit on 15 January 2001, two days after the domain was registered by Jimmy Wales and Larry Sanger. Its technological and conceptual underpinnings predate this; the earliest known proposal for an online encyclopedia was made by Rick Gates in 1993, and the concept of a free-as-in-freedom online encyclopedia was proposed by Richard Stallman in December 2000.

Interwiki links links between internet wikis

Interwiki linking (W-link) is a facility for creating links to the many wikis on the World Wide Web. Users avoid pasting in entire URLs and instead use a shorthand similar to links within the same wiki.

The Semantic Web is an extension of the World Wide Web through standards set by the World Wide Web Consortium (W3C). The goal of Semantic Web is to make Internet data machine-readable. To enable the encoding of semantics with the data, technologies such as Resource Description Framework (RDF) and Web Ontology Language (OWL) are used. These technologies are used to formally represent metadata. For example, ontology can describe concepts, relationships between entities, and categories of things. These embedded semantics offer significant advantages such as reasoning over data and operating with heterogeneous data sources.

The Resource Description Framework (RDF) is a family of World Wide Web Consortium (W3C) specifications originally designed as a metadata data model. It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax notations and data serialization formats. It is also used in knowledge management applications.

MediaWiki Wiki software

MediaWiki is a free and open-source wiki engine. It was developed for use on Wikipedia in 2002, and given the name "MediaWiki" in 2003. It remains in use on Wikipedia and almost all other Wikimedia websites, including Wiktionary, Wikimedia Commons and Wikidata; these sites continue to define a large part of the requirement set for MediaWiki. MediaWiki was originally developed by Magnus Manske and improved by Lee Daniel Crocker. Its development has since then been coordinated by the Wikimedia Foundation.

English Wikipedia English‑language edition of the free online encyclopedia

The English Wikipedia is the English-language edition of the free online encyclopedia Wikipedia. Founded on 15 January 2001, it is the first edition of Wikipedia and, as of April 2019, has the most articles of any of the editions. As of January 2020, 12% of articles in all Wikipedias belong to the English-language edition. This share has gradually declined from more than 50 percent in 2003, due to the growth of Wikipedias in other languages. As of 14 January 2020, there are 5,994,973 articles on the site, having surpassed the 5 million mark on 1 November 2015. In October 2015, the combined text of the English Wikipedia's articles totalled 11.5 gigabytes when compressed.

German Wikipedia German language edition of Wikipedia

The German Wikipedia is the German-language edition of Wikipedia, a free and publicly editable online encyclopedia.

A semantic wiki is a wiki that has an underlying model of the knowledge described in its pages. Regular, or syntactic, wikis have structured text and untyped hyperlinks. Semantic wikis, on the other hand, provide the ability to capture or identify information about the data within pages, and the relationships between pages, in ways that can be queried or exported like a database through semantic queries.

Wikimedia movement Social movement around Wikimedia including content publications, Wikimedia organizations, and independent editors

The Wikimedia movement, or simply Wikimedia, is the global community of contributors to Wikimedia Foundation projects. The movement was created around Wikipedia's community, and has since expanded to the other Wikimedia projects, including the commons projects Wikimedia Commons and Wikidata, and volunteer software developers contributing to MediaWiki. These volunteers are supported by numerous organizations around the world, including the Wikimedia Foundation, related chapters, thematic organizations, and user groups.

Semantic MediaWiki software for creating, managing and sharing structured data in MediaWiki

Semantic MediaWiki (SMW) is an extension to MediaWiki that allows for annotating semantic data within wiki pages, thus turning a wiki that incorporates the extension into a semantic wiki. Data that has been encoded can be used in semantic searches, used for aggregation of pages, displayed in formats like maps, calendars and graphs, and exported to the outside world via formats like RDF and CSV.

Wikipedia Free online encyclopedia that anyone can edit

Wikipedia is a multilingual online encyclopedia created and maintained as an open collaboration project by a community of volunteer editors using a wiki-based editing system. It is the largest and most popular general reference work on the World Wide Web, and is one of the most popular websites ranked by Alexa as of January 2020. It features exclusively free content and no commercial ads, and is owned and supported by the Wikimedia Foundation, a non-profit organization funded primarily through donations.

DBpedia Online database project

DBpedia is a project aiming to extract structured content from the information created in the Wikipedia project. This structured information is made available on the World Wide Web. DBpedia allows users to semantically query relationships and properties of Wikipedia resources, including links to other related datasets. Tim Berners-Lee described DBpedia as one of the most famous parts of the decentralized Linked Data effort.

History of wikis history of wiki collaborative platforms

The history of wikis is generally dated from 1994, when Ward Cunningham gave the name "WikiWikiWeb" to the knowledge base, which ran on his company's website at c2.com, and the wiki software that powered it. c2.com thus became the first true wiki, or a website with pages and links that can be easily edited via the browser, with a reliable version history for each page. He chose "WikiWikiWeb" as the name based on his memories of the "Wiki Wiki Shuttle" at Honolulu International Airport, and because "wiki" is the Hawaiian word for "quick".

Spanish Wikipedia Spanish language edition of Wikipedia

The Spanish Wikipedia is a Spanish-language edition of Wikipedia, a free, online encyclopedia. It has 1,559,898 articles. Started in May 2001, it reached 100,000 articles on March 8, 2006 and 1,000,000 articles on May 16, 2013. It is the 9th-largest Wikipedia as measured by the number of articles and has the 4th-largest number of edits.

Wikimedia Commons free-use media repository

Wikimedia Commons is an online repository of free-use images, sounds, other media, and JSON files. It is a project of the Wikimedia Foundation.

Freebase was a large collaborative knowledge base consisting of data composed mainly by its community members. It was an online collection of structured data harvested from many sources, including individual, user-submitted wiki contributions. Freebase aimed to create a global resource that allowed people to access common information more effectively. It was developed by the American software company Metaweb and ran publicly beginning in March 2007. Metaweb was acquired by Google in a private sale announced 16 July 2010. Google's Knowledge Graph was powered in part by Freebase.

Outline of Wikipedia Overview of and topical guide to Wikipedia

The following outline is provided as an overview of and topical guide to Wikipedia:

Volapük Wikipedia Volapük-language edition of Wikipedia

The Volapük Wikipedia is the Volapük-language edition of the free online encyclopedia Wikipedia. It was created in February 2003, but launched in January 2004. As of January 2017, it was the 60th-largest Wikipedia as measured by the number of articles, with about 124,000 articles, and the second-largest Wikipedia in a constructed language after the Esperanto Wikipedia.

Commercial use of Wikimedia projects refers to any business or product selling content from Wikipedia or Wikimedia projects which it freely took. Wikimedia projects use free and open copyright licenses which means that anyone may share the information for any purpose.

References

  1. https://www.wikidata.org/wiki/Wikidata:Introduction.
  2. From Freebase to Wikidata: The Great Migration; quote: Another example is Wikidata, a collaborative knowledgebase developed by Wikimedia Deutschland since 2012 and operated by the Wikimedia Foundation..
  3. "wikidata.org Competitive Analysis, Marketing Mix and Traffic - Alexa". www.alexa.com. Retrieved 13 January 2020.
  4. 1 2 Wikidata (Archived October 30, 2012, at WebCite )
  5. "Data Revolution for Wikipedia". Wikimedia Deutschland. March 30, 2012. Archived from the original on September 11, 2012. Retrieved September 11, 2012.
  6. "Wikibase — Home".
  7. "Wikidata:Database reports/List of properties/Top100".
  8. "Help:Statements".
  9. "Help:Data type".
  10. "Help:Property constraints portal".
  11. "Help:Sources".
  12. "Wikidata - Lexicographical data documentation".
  13. Dickinson, Boonsri (March 30, 2012). "Paul Allen Invests In A Massive Project To Make Wikipedia Better". Business Insider. Retrieved September 11, 2012.
  14. Perez, Sarah (March 30, 2012). "Wikipedia's Next Big Thing: Wikidata, A Machine-Readable, User-Editable Database Funded By Google, Paul Allen And Others". TechCrunch. Archived from the original on September 11, 2012. Retrieved September 11, 2012.
  15. "Wikidata - Meta".
  16. Pintscher, Lydia (October 30, 2012). "wikidata.org is live (with some caveats)". wikidata-l (Mailing list). Retrieved November 3, 2012.
  17. Roth, Matthew (March 30, 2012). "The Wikipedia data revolution". Wikimedia Foundation. Archived from the original on September 11, 2012. Retrieved September 11, 2012.
  18. Pintscher, Lydia (14 January 2013). "First steps of Wikidata in the Hungarian Wikipedia". Wikimedia Deutschland. Retrieved 17 December 2015.
  19. Pintscher, Lydia. "Wikidata coming to the next two Wikipedias". Wikimedia Deutschland. Retrieved January 31, 2013.
  20. Pintscher, Lydia (13 February 2013). "Wikidata live on the English Wikipedia". Wikimedia Deutschland. Retrieved 15 February 2013.
  21. Pintscher, Lydia (6 March 2013). "Wikidata now live on all Wikipedias". Wikimedia Deutschland. Retrieved 8 March 2013.
  22. "Wikidata ist für alle Wikipedien da" (in German). Golem.de. Retrieved 29 January 2014.
  23. "Wikipedia talk:Wikidata interwiki RFC". March 29, 2013. Retrieved March 30, 2013.
  24. Pintscher, Lydia (23 September 2013). "Wikidata is Here!". Commons:Village pump.
  25. Pintscher, Lydia. "Wikidata/Status updates/2013 03 01". Wikimedia Meta-Wiki. Wikimedia Foundation. Retrieved 3 March 2013.
  26. Pintscher, Lydia (27 March 2013). "You can have all the data!". Wikimedia Deutschland. Retrieved 28 March 2013.
  27. "Wikidata goes live worldwide". The H. 2013-04-25. Archived from the original on 3 January 2014.
  28. Lydia, Pintscher (16 September 2015). "Wikidata: Access to data from arbitrary items is here". Wikipedia:Village pump (technical) . Retrieved 30 August 2016.
  29. Lydia, Pintscher (27 April 2016). "Wikidata support: arbitrary access is here". Commons:Village pump . Retrieved 30 August 2016.
  30. https://query.wikidata.org/
  31. "Announcing the release of the Wikidata Query Service".
  32. "Wikidata Query Data tools".
  33. "First ODI Open Data Awards presented by Sirs Tim Berners-Lee and Nigel Shadbolt". Archived from the original on 2016-03-24.
  34. "Percentage of articles making use of data from Wikidata".
  35. "Wikidata Tools - Visualize data".
  36. "Scholia - Wikidata".
  37. "International Semantic Web Conference 2018".
  38. commons:File talk:Wikidata-logo-en.svg#Hybrid. Retrieved 2016-10-06.
  39. Rob Barry / Mwnci - Deep Spreadsheets · GitLab
  40. https://www.unicode.org/review/pri408/

Further reading