Architecture and Applications

Transcription

1 webinale The Web of Linked Data Architecture and Applications Prof. Dr. Christian Bizer Freie Universität Berlin

2 Outline 1. From a Web of Documents to a Web of Data Web APIs and Linked Data 2. Linked Data Deployment on the Web What data is out there? 3. Linked Data Applications What is being done with the data? 4. Economic Opportunities What does this mean for start-ups?

3 The Classic Web Single Global Information Space Web Browsers Search Engines 1. URLs as HTML HTML HTML globally unique IDs retrieval mechanism 2. HTML as shared content format 3. Hyperlinks hyperlinks A B C

4 Problem and Solution Problem As Web content is only loosely structured it is difficult for applications to do smart things with it. Solution Increase the structure of Web content.

5 Web APIs and Mashups

6 Web APIs and Mashups Web API Mashup Up Web API Web API Web API A B C D Shortcomings 1. APIs provide proprietary p interfaces 2. Mashups are based on a fixed set of data sources. 3. You can not set hyperlinks between data objects.

7 Web APIs slice the Web into Walled Gardens Image: Bob Jagensdorf, CC-BY

8 Linked Data Extend the Web with a single global data space, which enables applications to 1. discover new data sources at run-time 2. integrate data from different sources link links links links A B C D E

9 Linked Data Use Semantic Web technologies to 1. publish structured data on the Web, 2. set links between data from one data source to data within other data sources. link links links links A B C D E

10 The Data Model pd:cygri rdf:type foaf:person foaf:namef Richard Cyganiak foaf:based_near dbpedia:berlin

11 Data items are identified with HTTP URIs pd:cygri rdf:type foaf:person foaf:namef Richard Cyganiak foaf:based_near dbpedia:berlin pd:cygri = dbpedia:berlin =

12 Resolving URIs over the Web pd:cygri rdf:type foaf:person foaf:namef Richard Cyganiak foaf:based_near dbpedia:berlin dp:population skos:subject dp:cities_in_germany i

13 Dereferencing URIs over the Web pd:cygri rdf:type foaf:person foaf:namef Richard Cyganiak foaf:based_near dbpedia:berlin dp:population dbpedia:hamburgdi b skos:subject skos:subject dp:cities_in_germany i dbpedia:muenchen skos:subject

14 The Disco Hyperdata Browser

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16 Properties of the Web of Linked Data Anyone can publish data to the Web of Linked Data Data items are connected by links creating a global data graph that spans data sources and enables the discovery of new data sources. All data sources provide the same API URI dereferencing, SPARQL endpoint (optional) The Web of Data is open meaning that applications can discover new data sources at run-time by following links. Data is self-descriptive If an application encounters data represented using an unfamiliar vocabulary, the application can resolve the URIs that identify vocabulary terms in order to find their S or OWL definition.

17 2. Linked Data Deployment on the Web Is this real? link links links links A B C D E

18 W3C Linking Open Data Project Grassroots community effort to publish existing open license datasets as Linked Data on the Web interlink things between different data sources

19 LOD Datasets on the Web: May 2007 Over 500 million triples Around 120,000 links between data sources

20 LOD Datasets on the Web: September 2008

21 LOD Datasets on the Web: July 2009 Over 13.1 billion triples Over 142 million links between data sources

22 DBpedia An Interlinking Hub in the Web of Data

23 DBpedia An Interlinking Hub in the Web of Data DBpedia is a community effort to extract structured information from Wikipedia make this information available on the Web under an open license set links to other datasets on the Web of Linked Data Contributors Freie Universität Berlin (Germany) Universität Leipzig (Germany) OpenLink Software (UK) neofonie (Germany)

24 Extracting Structured Information from Wikipedia < dbpedia:native_name Calgary ; dbpedia:elevation 1048 ; dbpedia:population_city ; dbpedia:population_metro di t ; mayor_name dbpedia:dave_bronconnier ; governing_body dbpedia:calgary_city_council _ ;...

25 The DBpedia Dataset Data about 3.4 million things including at least 312,000 persons 140,000 organizations 413,000 places 94,000 music albums 49,000 films 15,000 video games 146,000 species Altogether more than 1 billion pieces of information ( triples) labels and abstracts in 92 different languages 841,000 links to images 5,081,000, links to external web pages 9,393,000 external links into other datasets

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27 The LOD project is loosing track with the diagram LOD Datasets on the Web: July 2009

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30 Libraries Institutions publishing Linked Data Library of Congress (subject headings) Schwedische Nationalbibliothek (Libris - catalog) Hungarian National Library (OPAC and Digital Library) Deutschen Zentralbibliothek für Wirtschaftswissenschaften (subject headings) Deutsche Nationalbibliothek (PND dataset and subject headings) Workshop: Semantic Web in Bibliotheken (SWIB09) Köln, 24. und 25. November W3C Library Linked Data Incubator Group

31 Media Industry

32 a: Embed into HTML Pages Alternative option to /XML for publishing Linked Data Similar to micro formats, but more flexible Websites publishing a Newsweek BBC TIME BestBuy Peek & Cloppenburg IMDb Posterous Rotten Tomatoes Yelp..

33 Connecting the classic Web and Linked Data Annotate Web documents with Linked Data URIs < dc:subject < Goals Connect everything. Display Web of Data content as info boxes next to news or blog posts. Improve search by using Linked Data as background knowledge. (Semi-) Automated Annotation Services using Named Entity Recognition Open Calais (Thomsons Reuters) for news Zemanta (startup) for blog posts

34 3. Linked Data Applications What can I do with this? Linked Data Browsers Linked Data Mashups Search Engines Thing Thing Thing Thing Thing Thing Thing Thing Thing Thing typed links typed typed typed links links links A B C D E

35 Linked Data Browsers Tabulator Browser (MIT, USA) Marbles (FU Berlin, DE) OpenLink Browser (OpenLink, UK) Zitgist Browser (Zitgist, USA) Humboldt (HP Labs, UK) Disco Hyperdata Browser (FU Berlin, DE) Fenfire (DERI, Irland)

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37 DBpedia Mobile Displays Wikipedia data on a map Smushes the data with data from other sources

38 Web of Data Search Engines Falcons (IWS, China) Sig.ma (DERI, Ireland) Swoogle (UMBC, USA) VisiNav (DERI, Ireland) Watson (Open University, UK)

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42 What are the big players doing? Yahoo! and Google have started to crawl Linked Data in its a serialization as well as Microformats. Yahoo! provides access to crawled data through the Yahoo BOSS API is using the data within Yahoo Search Monkey to make search results more useful and visually appealing. Google uses crawled data for its Social Graph API is planning to / uses crawled data to enhance search results snippets for reviews and people.

43 Yahoo! Search Monkey

44 Facebook consumes a

45 Summary The Web of Linked Data is growing rapidly more and more data is becoming available. more and more applications are being developed. Compared to proprietary Web 2.0 APIs Linked Data provides standardized data access interfaces. allows developers to use a wide range of open source tools to store and process Web data.

46 4. Economic Opportunities What does this mean for start-ups?

47 Huge Reservoir of Free Content can be used to provide background facts about places, people, topics Background Facts

48 Lower Data Integration Costs within specific communities Libraries Life Sciences Government Departments Integration Effort by Data Consumer potential cost savers standard data model standard interfaces Reduce duplicate integration work Publisher Effort Third Party Effort Consumer Effort

49 Options for Consulting Companies existing Linked Data consulting companies.

50 Options for Infrastructure Companies existing Linked Data infrastructure companies and tools vendors.

51 Options for Search Companies 1. new vertical search engines Sig.ma, FalconS, Be aware the Yahoo and Google are not sleeping. 2. improving text search with background knowledge

52 Options for Data Integration Intermediaries business model crawl, integrate and clean Web data sell clean data to subscribers existing Linked Data integration intermediaries

53 Thanks! References Overview Article Christian Bizer, Tom Heath, Tim Berners-Lee: Linked Data The Story So Far Linking Open Data Project Wiki Tutorial on How to Publish Linked Data on the Web 3 rd Linked Data on the Web Workshop at WWW2010