Wikidata Explained
Wikidata should not be confused with WibiData.
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Wikidata |
Wikidata is a collaboratively edited multilingual knowledge graph hosted by the Wikimedia Foundation.[1] It is a common source of open data that Wikimedia projects such as Wikipedia,[2] and anyone else, is able to use under the CC0 public domain license. Wikidata is a wiki powered by the software MediaWiki, including its extension for semi-structured data, the Wikibase. As of mid-2024, Wikidata had 1.57 billion item statements (semantic triple).[3]
Concept
Wikidata is a document-oriented database, focusing on items, which represent any kind of topic, concept, or object. Each item is allocated a unique, persistent identifier, a positive integer prefixed with the upper-case letter Q, known as a "QID". Q is the starting letter of the first name of Qamarniso Vrandečić (née Ismoilova), an Uzbek Wikimedian married to the Wikidata co-developer Denny Vrandečić.[4] This enables the basic information required to identify the topic that the item covers to be translated without favouring any language.
Examples of items include,,,, and .
Item labels do not need to be unique. For example, there are two items named "Elvis Presley":, which represents the American singer and actor, and, which represents his self-titled album. However, the combination of a label and its description must be unique. To avoid ambiguity, an item's unique identifier (QID) is hence linked to this combination.
Main parts
Fundamentally, an item consists of:
- An identifier (the QID), related to a label and a description.
- Optionally, multiple aliases and some number of statements (and their properties and values).
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 entity 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 with the value under the item .
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.[5]
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 may only be paired with values of type "URL".[6]
Optionally, qualifiers can be used to refine the meaning of a statement by providing additional information. For example, a "population" statement could be modified with a qualifier such as "point in time (P585): 2011" (as its own key-value pair). Values in the statements may also be annotated with references, pointing to a source backing up the statement's content.[7] As with statements, all qualifiers and references are property–value pairs.
Properties
Each property has a numeric identifier prefixed with a capital P and a page on Wikidata with optional label, description, aliases, and statements. As such, there are properties with the sole purpose of describing other properties, such as .
Properties may also define more complex rules about their intended usage, termed constraints. For example, the property includes a "single value constraint", reflecting the reality that (typically) territories have only one capital city. Constraints are treated as testing alerts and hints, rather than inviolable rules.[8]
Before a new property is created, it needs to undergo a discussion process.[9] [10]
The most used property is, which is used on more than item pages [11]
Lexemes
In linguistics, a lexeme is a unit of lexical meaning representing a group of words that share the same core meaning and grammatical characteristics.[12] Similarly, Wikidata's lexemes are items with a structure that makes them more suitable to store lexicographical data. Since 2016, Wikidata has supported lexicographical entries in the form of lexemes.
In Wikidata, lexicographical entries have a different identifier from regular item entries. These entries are prefixed with the letter L, such as in the example entries for book and cow. Lexicographical entries in Wikidata can contain statements, senses, and forms.[13] The use of lexicographical entries in Wikidata allows for the documentation of word usage, the connection between words and items on Wikidata, word translations, and enables machine-readable lexicographical data.
In 2020, lexicographical entries on Wikidata exceeded 250,000. The language with the most lexicographical entries was Russian, with a total of 101,137 lexemes, followed by English with 38,122 lexemes. There are over 668 languages with lexicographical entries on Wikidata.[14]
Entity Schemas
In Wikidata, a schema is a data model that outlines the necessary attributes for a data item.[15] [16] For instance, a data item that uses the attribute "instance of" with the value "human" would typically include attributes such as "place of birth," "date of birth," "date of death," and "place of death." The entity schema in Wikidata utilizes Shape Expression (ShEx) to describe the data in Wikidata items in the form of a Resource Description Framework (RDF). The use of entity schemas in Wikidata helps address data inconsistencies and unchecked vandalism.
In January 2019, development started of a new extension for MediaWiki to enable storing ShEx in a separate namespace.[17] [18] Entity schemas are stored with different identifiers than those used for items, properties, and lexemes. Entity schemas are stored with an "E" identifier, such as E10 for the entity schema of human data instances and E270 for the entity schema of building data instances. This extension has since been installed on Wikidata[19] and enables contributors to use ShEx for validating and describing Resource Description Framework data in items and lexemes. Any item or lexeme on Wikidata can be validated against an Entity Schema, and this makes it an important tool for quality assurance.
Content
Wikidata's content collections include data for biographies,[20] medicine,[21] digital humanities,[22] scholarly metadata through the WikiCite project.[23]
It includes data collections from other open projects including Freebase (database).[24]
Development
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.[25] [26] The development of the project is mainly driven by Wikimedia Deutschland under the management of Lydia Pintscher, and was originally split into three phases:[27]
- Centralising interlanguage links – links between Wikipedia articles about the same topic in different languages.
- Providing a central place for infobox data for all Wikipedias.
- Creating and updating list articles based on data in Wikidata and linking to other Wikimedia sister projects, including Meta-Wiki and the own Wikidata (interwikilinks).
Initial rollout
Wikidata was launched on 29 October 2012 and was the first new project of the Wikimedia Foundation since 2006.[28] [29] [30] 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 (interwikipedia links).
Historically, a Wikipedia article would include a list of interlanguage links (links to articles on the same topic in other editions of Wikipedia, if they existed). Wikidata was originally a self-contained repository of interlanguage links.[31] 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.[32] 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.[33] [34] [35] [36] After no consensus was reached over a proposal to restrict the removal of language links from the English Wikipedia,[37] they were automatically removed by bots. On 23 September 2013, interlanguage links went live on Wikimedia Commons.[38]
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.[39]
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.[40] [41] On 16 September 2015, Wikidata began allowing so-called arbitrary access, or access from a given article of a Wikipedia to the statements on Wikidata 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.[42] On 27 April 2016, arbitrary access was activated on Wikimedia Commons.[43]
According to a 2020 study, a large proportion of the data on Wikidata consists of entries imported en masse from other databases by Internet bots, which helps to "break down the walls" of data silos.[44]
Query service and other improvements
On 7 September 2015, the Wikimedia Foundation announced the release of the Wikidata Query Service,[45] which lets users run queries on the data contained in Wikidata.[46] The service uses SPARQL as the query language. As of November 2018, there are at least 26 different tools that allow querying the data in different ways.[47] It uses Blazegraph as its triplestore and graph database.[48]
In 2021, Wikimedia Deutschland released the Query Builder,[49] "a form-based query builder to allow people who don't know how to use SPARQL" to write a query.
Logo
The bars on the logo contain the word "WIKI" encoded in Morse code.[50] It was created by Arun Ganesh and selected through community decision.[51]
Reception
In November 2014, Wikidata received the Open Data Publisher Award from the Open Data Institute "for sheer scale, and built-in openness".[52]
In December 2014, Google announced that it would shut down Freebase in favor of Wikidata.[53]
, Wikidata information was 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.[54]
, Wikidata's data was visualized by at least 20 other external tools[55] and over 300 papers have been published about Wikidata.[56]
Applications
A systematic literature review of the uses of Wikidata in research was carried out in 2019.[60]
See also
Further reading
External links
Notes and References
- News: Chalabi. Mona. April 26, 2013. Welcome to Wikidata! Now what?. October 2, 2021. 2 October 2021. https://web.archive.org/web/20211002152920/https://www.theguardian.com/news/datablog/2013/apr/26/wikidata-launch. live.
- Web site: Data Revolution for Wikipedia . March 30, 2012 . Wikimedia Deutschland . September 11, 2012 . https://web.archive.org/web/20121023170149/http://www.wikimedia.de/wiki/Pressemitteilungen/PM_3_12_Wikidata_EN . October 23, 2012 . live.
- Web site: Grafana . 2024-03-21 . grafana.wikimedia.org.
- Book: Vrandečić . Denny . Pintscher . Lydia . Krötzsch . Markus . Companion Proceedings of the ACM Web Conference 2023 . Wikidata: The Making of . 30 April 2023 . 615–624 . https://dl.acm.org/doi/10.1145/3543873.3585579 . 10.1145/3543873.3585579. 9781450394192 . 258377705 .
- Web site: Help:Statements – Wikidata. www.wikidata.org. 20 February 2019. 25 March 2019. https://web.archive.org/web/20190325054926/https://www.wikidata.org/wiki/Help:Statements. live.
- Web site: Help:Data type – Wikidata. www.wikidata.org. 20 February 2019. 23 March 2019. https://web.archive.org/web/20190323184623/https://www.wikidata.org/wiki/Help:Data_type. live.
- Web site: Help:Sources – Wikidata. www.wikidata.org. 20 February 2019. 17 April 2019. https://web.archive.org/web/20190417231251/https://www.wikidata.org/wiki/Help:Sources. live.
- Web site: Help:Property constraints portal. Wikidata. 20 February 2019. 1 June 2019. https://web.archive.org/web/20190601180538/https://www.wikidata.org/wiki/Help:Property_constraints_portal. live.
- Web site: Wikidata as a digital preservation knowledgebase. Cochrane. Euan. 30 September 2016. openpreservation.org. 5 January 2022. 5 January 2022. https://web.archive.org/web/20220105110113/https://openpreservation.org/blogs/wikidata-as-a-digital-preservation-knowledgebase/. live.
- Samuel . John . Experimental IR Meets Multilinguality, Multimodality, and Interaction . Analyzing and Visualizing Translation Patterns of Wikidata Properties . Lecture Notes in Computer Science . Experimental IR Meets Multilinguality, Multimodality, and Interaction . CLEF 2018 . 15 August 2018 . 11018 . 129 . 10.1007/978-3-319-98932-7_12 . 978-3-319-98931-0 . https://books.google.com/books?id=hD5qDwAAQBAJ&pg=PA129.
- Web site: Wikidata:Database reports/List of properties/Top100. 18 November 2023. 24 February 2023. https://web.archive.org/web/20230224212120/https://www.wikidata.org/wiki/Wikidata:Database_reports/List_of_properties/Top100. live.
- Book: Bonami, Olivier . The Lexeme In Descriptive And Theoretical Morphology . Boyé . Gilles . Dal . Georgette . Giraudo . Hélène . Namer . Fiammetta . 2018-08-23 . [object Object] . 10.5281/zenodo.1402520.
- Web site: Wikidata:Lexicographical data/Documentation – Wikidata . live . https://web.archive.org/web/20181113210533/https://www.wikidata.org/wiki/Wikidata:Lexicographical_data/Documentation . 13 November 2018 . 13 November 2018 . www.wikidata.org.
- Nielsen . Finn . 2020-05 . Ionov . Maxim . McCrae . John P. . Chiarcos . Christian . Declerck . Thierry . Bosque-Gil . Julia . Gracia . Jorge . Lexemes in Wikidata: 2020 status . Proceedings of the 7th Workshop on Linked Data in Linguistics (LDL-2020) . English . Marseille, France . European Language Resources Association . 82–86 . 979-10-95546-36-8.
- Book: Werkmeister, Lucas . Schema Inference of Wikidata . 2018 . . 2018 . Karlsruhe . en-GB.
- Hernández, Daniel; Hogan, Aidan; Krötzsch, M. (2015). "Reifying RDF: What Works Well With Wikidata?".
- Web site: Extension:EntitySchema – MediaWiki . 10 September 2021 . mediawiki.org . 25 June 2021 . https://web.archive.org/web/20210625050439/https://www.mediawiki.org/wiki/Extension:EntitySchema . live .
- Web site: Initial empty repository. Gerrit. 15 January 2019. 12 June 2022. 19 March 2022. https://web.archive.org/web/20220319091240/https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/EntitySchema/+/26654db17345beefbd5518af48ed1bcd17288bc9. live.
- Web site: Version – Wikidata . 10 September 2021 . Wikidata.org . 19 October 2021 . https://web.archive.org/web/20211019080834/https://www.wikidata.org/wiki/Special:Version . live .
- Chisholm . Andrew . Radford . Will . Hachey . Ben . Learning to generate one-sentence biographies from Wikidata . 2017 . 1702.06235.
- Turki . Houcemeddine . Shafee . Thomas . Hadj Taieb . Mohamed Ali . Ben Aouicha . Mohamed . Vrandečić . Denny . Das . Diptanshu . Hamdi . Helmi . Wikidata: A large-scale collaborative ontological medical database . Journal of Biomedical Informatics . November 2019 . 99 . 103292 . 10.1016/j.jbi.2019.103292.
- Zhao . Fudie . A systematic review of Wikidata in Digital Humanities projects . Digital Scholarship in the Humanities . 31 May 2023 . 38 . 2 . 852–874 . 10.1093/llc/fqac083. free .
- Book: Nielsen . Finn Årup . Mietchen . Daniel . Willighagen . Egon . Scholia, Scientometrics and Wikidata . The Semantic Web: ESWC 2017 Satellite Events . Lecture Notes in Computer Science . 2017 . 10577 . 237–259 . 10.1007/978-3-319-70407-4_36. 978-3-319-70406-7 . https://backend.orbit.dtu.dk/ws/files/139322959/460065_Print.pdf .
- Pellissier Tanon . Thomas . Vrandečić . Denny . Schaffert . Sebastian . Steiner . Thomas . Pintscher . Lydia . From Freebase to Wikidata: The Great Migration . 11 April 2016 . 1419–1428 . 10.1145/2872427.2874809.
- News: Paul Allen Invests In A Massive Project To Make Wikipedia Better . Boonsri . Dickinson . Business Insider . March 30, 2012 . September 11, 2012 . 23 December 2017 . https://web.archive.org/web/20171223215904/http://www.businessinsider.com/paul-allen-invests-in-wikidata-project-2012-3?IR=T . live .
- News: Wikipedia's Next Big Thing: Wikidata, A Machine-Readable, User-Editable Database Funded By Google, Paul Allen And Others . Sarah . Perez . TechCrunch . March 30, 2012 . September 11, 2012 . https://web.archive.org/web/20121005062200/http://techcrunch.com/2012/03/30/wikipedias-next-big-thing-wikidata-a-machine-readable-user-editable-database-funded-by-google-paul-allen-and-others/ . October 5, 2012 . live.
- Web site: Wikidata – Meta. meta.wikimedia.org. 8 November 2015. 7 April 2012. https://web.archive.org/web/20120407213951/http://meta.wikimedia.org/wiki/Wikidata. live.
- http://www.wikidata.org Wikidata
- wikidata.org is live (with some caveats) . October 30, 2012 . November 3, 2012 . wikidata-l . Pintscher . Lydia.
- News: The Wikipedia data revolution . Matthew . Roth . Wikimedia Foundation . March 30, 2012 . September 11, 2012 . https://web.archive.org/web/20200731012340/https://diff.wikimedia.org/2012/03/30/the-wikipedia-data-revolution/ . July 31, 2020 . live.
- Book: Leitch, Thomas. Thomas Leitch. Wikipedia U: Knowledge, Authority, and Liberal Education in the Digital Age. 2014-11-01. Johns Hopkins University Press. 978-1-4214-1550-5. en. 120.
- Web site: First steps of Wikidata in the Hungarian Wikipedia . Wikimedia Deutschland . 14 January 2013 . 17 December 2015 . Pintscher, Lydia . 14 December 2015 . https://web.archive.org/web/20151214085628/https://blog.wikimedia.de/2013/01/14/first-steps-of-wikidata-in-the-hungarian-wikipedia/ . live .
- Web site: Wikidata coming to the next two Wikipedias . Wikimedia Deutschland . January 31, 2013 . Pintscher, Lydia . 2013-01-30 . 4 October 2018 . https://web.archive.org/web/20181004022937/http://blog.wikimedia.de/2013/01/30/wikidata-coming-to-the-next-two-wikipedias/ . live .
- Web site: Wikidata live on the English Wikipedia . Wikimedia Deutschland . 13 February 2013 . 15 February 2013 . Pintscher, Lydia . 19 February 2013 . https://web.archive.org/web/20130219054033/http://blog.wikimedia.de/2013/02/13/wikidata-live-on-the-english-wikipedia/ . live .
- Web site: Wikidata now live on all Wikipedias . Wikimedia Deutschland . 6 March 2013 . 8 March 2013 . Pintscher, Lydia . 14 April 2013 . https://web.archive.org/web/20130414150512/http://blog.wikimedia.de/2013/03/06/wikidata-now-live-on-all-wikipedias/ . live .
- News: Wikidata ist für alle Wikipedien da . Golem.de . de . 29 January 2014 . 6 November 2018 . https://web.archive.org/web/20181106213849/https://www.golem.de/news/onlineenzyklopaedie-wikidata-ist-fuer-alle-wikipedien-da-1304-98941.html . live .
- Web site: Wikipedia talk:Wikidata interwiki RFC . March 29, 2013 . March 30, 2013 . 18 October 2021 . https://web.archive.org/web/20211018115922/https://en.wikipedia.org/w/index.php?title=Wikipedia_talk%3AWikidata_interwiki_RFC&oldid=547663432 . live .
- News: Pintscher. Lydia. Wikidata is Here!. Commons:Village pump. 23 September 2013. 30 August 2016. 6 December 2021. https://web.archive.org/web/20211206060438/https://commons.wikimedia.org/wiki/Commons:Village_pump/Archive/2013/10#Wikidata_is_here.21. live.
- Web site: Pintscher. Lydia. Wikidata/Status updates/2013 03 01. Wikimedia Meta-Wiki. Wikimedia Foundation. 3 March 2013. 12 April 2013. https://web.archive.org/web/20130412004917/http://meta.wikimedia.org/wiki/Wikidata/Status_updates/2013_03_01. live.
- Web site: Pintscher . Lydia . You can have all the data! . Wikimedia Deutschland . 27 March 2013 . 28 March 2013 . 29 March 2013 . https://web.archive.org/web/20130329234058/http://blog.wikimedia.de/2013/03/27/you-can-have-all-the-data/ . live .
- News: Wikidata goes live worldwide . The H . https://web.archive.org/web/20140101031329/http://www.h-online.com/open/news/item/Wikidata-goes-live-worldwide-1849479.html . 1 January 2014 . 2013-04-25 .
- News: Pintscher. Lydia. Wikidata: Access to data from arbitrary items is here. 30 August 2016. 16 September 2015. . 27 September 2016. https://web.archive.org/web/20160927063804/https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)/Archive_140#Wikidata:_Access_to_data_from_arbitrary_items_is_here. live.
- News: Pintscher. Lydia. Wikidata support: arbitrary access is here. 30 August 2016. 27 April 2016. Commons:Village pump. 5 February 2017. https://web.archive.org/web/20170205224443/https://commons.wikimedia.org/wiki/Commons:Village_pump/Archive/2016/05#Wikidata_support:_arbitrary_access_is_here. live.
- Waagmeester, Andra. Stupp, Gregory. Burgstaller-Muehlbacher, Sebastian. Good, Benjamin M. Griffith, Malachi. Griffith, Obi L. Hanspers, Kristina. Hermjakob, Henning. Hudson, Toby S. Hybiske, Kevin. free.
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- Web site: Wikidata:Tools/Query data – Wikidata. www.wikidata.org. 13 November 2018. 31 May 2020. https://web.archive.org/web/20200531044004/https://www.wikidata.org/wiki/Wikidata:Tools/Query_data. live.
- Web site: Wikidata-tech Wikidata Query Backend Update (take two!). en. lists.wikimedia.org. 2018-08-29. 6 January 2021. https://web.archive.org/web/20210106191817/https://lists.wikimedia.org/pipermail/wikidata-tech/2015-March/000740.html. live. (The message also contains a link to the graph databases comparison performed by Wikimedia.)
- Web site: Wikidata Query Builder. query.wikidata.org.
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- Web site: First ODI Open Data Awards presented by Sirs Tim Berners-Lee and Nigel Shadbolt. https://web.archive.org/web/20160324003214/http://theodi.org/news/first-odi-open-data-awards-presented-by-sir-tim-berners-lee-and-sir-nigel-shadbolt. 2016-03-24.
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- Mora-Cantallops . Marçal . Sánchez-Alonso . Salvador . García-Barriocanal . Elena . A systematic literature review on Wikidata . Data Technologies and Applications . 2 September 2019 . 53 . 3 . 250–268 . 10.1108/DTA-12-2018-0110. 202036639 .