Semantic Wikipedia Max Völkel, Markus Krötzsch, Denny Vrandecic, Heiko Haller, Rudi Studer Institute AIFB, University of Karlsruhe (TH) 76128 Karlsruhe, Germany {voelkel,kroetzsch,vrandecic,haller,studer}@aifb.uni-karlsruhe.de ABSTRACT Wikipedia is the world’s largest collaboratively edited source of encyclopaedic knowledge. But its contents are barely machine- interpretable. Structural knowledge, e. g. about how concepts are interrelated, can neither be formally stated nor automatically processed. Also the wealth of numerical data is only available as plain text and thus can not be processed by its actual meaning. We provide an extension to be integrated in Wikipedia, that al- lows the typing of links between articles and the specification of typed data inside the articles in an easy-to-use manner. Enabling even casual users to participate in the creation of an open semantic knowledge base, Wikipedia has the chance to be- come a resource of semantic statements, hitherto unknown regard- ing size, scope, openness, and internationalisation. These semantic enhancements bring to Wikipedia benefits of today’s semantic tech- nologies: more specific ways of searching and browsing. Also, the RDF export, that gives direct access to the formalised knowledge, opens Wikipedia up to a wide range of external applications, that will be able to use it as a background knowledge base. Keywords Semantic Web, Wikipedia, RDF, Wiki 1. INTRODUCTION This paper describes an extension to be integrated in Wikipedia, that enhances it with Semantic Web [1] technologies. Wikipedia, the free encyclopaedia, is well-established as the world’s largest on- line collection of encyclopaedic knowledge, also being an example of global collaboration within an open community of volunteers. Using Wikipedia currently means reading articles—There is no way to automatically gather information scattered across multiple articles, like “Give me a table of all movies from the 1960s with Italian directors”. Although the data is quite structured (each movie on its own article, links to actors and directors), its meaning is un- clear to the computer, because it is not represented in a machine- processable, i. e. formalised way. To let the huge and highly motivated community of Wikipedians render the shared factual knowledge of Wikipedia machine-pro- Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Demos and Posters of the 3rd European Semantic Web Conference (ESWC 2006), Budva, Montenegro, 11th - 14th June, 2006 Copyright 2006 ACM X-XXXXX-XX-X/XX/XX ...$5.00. London is the capital city of England and of the United Kingdom. As of 2005, the total resident population of London was estimated 7,421,328. Greater London covers an area of 609 square miles. It is widely considered to be one of the world's four primary global cities (along with New York City, Tokyo and Paris). United Kingdom of Great Britain and Northern Ireland (usually shortened to the United Kingdom, or the UK) is one of two sovereign states occupying the British Isles in northwestern Europe, the other being the Republic of Ireland. The UK, with most of its territory and population on the island of Great Britain, shares a land border with the Republic of Ireland on the island of Ireland and is otherwise England is the most populous home nation of the United Kingdom (UK). It accounts for more than 83% of the total UK population, occupies most of the southern two-thirds of the island of Great Britain and shares land borders with Scotland, to the north, and Wales, to the west. 2005 (MMV) was a common year 1 Events 1.1 January 1.2 February 1.3 March 1.4 April 1.5 May 1.6 June 1.7 July New York City ofcially the City of New York, is the most populous city in the United States and the most densely populated major city in North America.r Paris is the capital and largest city of France. Straddling the river Seine in the country's north, it is a major global cultural and political centre in addition to being the world's most visited city. Tokyo () literally "eastern capital", is one of the 47 prefectures of Japan and includes the highly urbanized downtown area formerly known as the city of Tokyo London is the capital city of England and of the United Kingdom. As of 2005, the total resident population of London was estimated 7,421,328. Greater London covers an area of 609 square miles. It is widely considered to be one of the world's four primary global cities (along with New York City, Tokyo and Paris). United Kingdom of Great Britain and Northern Ireland (usually shortened to the United Kingdom, or the UK) is one of two sovereign states occupying the British Isles in northwestern Europe, the other being the Republic of Ireland. The UK, with most of its territory and population on the island of Great Britain, shares a land border with the Republic of Ireland on the island of Ireland and is otherwise England is the most populous home nation of the United Kingdom (UK). It accounts for more than 83% of the total UK population, occupies most of the southern two-thirds of the island of Great Britain and shares land borders with Scotland, to the north, and Wales, to the west. 2005 (MMV) was a common year 1 Events 1.1 January 1.2 February 1.3 March 1.4 April 1.5 May 1.6 June 1.7 July New York City ofcially the City of New York, is the most populous city in the United States and the most densely populated major city in North America.r Paris is the capital and largest city of France. Straddling the river Seine in the country's north, it is a major global cultural and political centre in addition to being the world's most visited city. Tokyo () literally "eastern capital", is one of the 47 prefectures of Japan and includes the highly urbanized downtown area formerly known as the city of Tokyo United Kingdom London England is capital of is capital of 1577303 km² population area 7421328 part of Figure 1: Currently there are pages and links (above), we fea- ture concepts and data connected by relations (below). cessable, we face several challenges: In addition to technical as- pects of this endeavour, the main challenge is to introduce semantic technologies into the established usage patterns of Wikipedia. We propose small extensions to the wiki link syntax and an enhanced article view to show the interpreted semantic data to the user. Pow- erful inline queries turn parts of a page into a dynamically updated list or table. These queries have the potential to replace the many hand-crafted lists (e. g. cities in Europe). We expose Wikipedia’s fine-grained human edited information in a machine-readable way by using the W3C standards on RDF, XSD, RDFS, and OWL. This opens new ways to improve Wiki- pedia’s capabilities for querying, aggregating, or exporting knowl- edge, based on well-established Semantic Web technologies. We hope that Semantic Wikipedia can help to demonstrate the promised value of semantic technologies to the general public. The primary goal of this project is to supply an implemented ex-