Consuming linked data by machines

Consuming Linked Data by Machines Consuming Linked Data Tutorial ISWC 2009, Washington DC Patrick Sinclair, BBC

RDF Resource Description Framework Juan introduced RDF earlier, and it’s one of the key elements to Linked Data as it’s how data is expressed on the web: when you want to fetch some information about a resource, it is returned in RDF.

RDF subject - predicate - object Coldplay is the artist of Viva la Vida Coldplay is the artist of Viva la Vida http://dbpedia.org/resource/Coldplay http://dbpedia.org/ontology/artist http://dbpedia.org/resource/Viva_la_Vida With RDF, you make statements about resources using subject-predicate-object expressions. * For example, if you want to say that “Coldplay is the artist of the album Viva la Vida”. * The subject is “Coldplay”, the predicate is “is the artist of”, and the “object” is “Viva la vida”. And in RDF we’re using URIs. * So there’s a URI for Coldplay And a URI for Viva la vida. And here is the URI for the property indicating the artist for an album.

prefix dbpedia-owl: <http://dbpedia.org/ontology/> prefix foaf: <http://xmlns.com/foaf/0.1/> prefix dbprop: <http://dbpedia.org/property/> prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> 51.507778 -0.128056 geo:lat geo:long http://dbpedia.org/resource/London dbprop:origin http://dbpedia.org/resource/Coldplay dbpedia-owl:artist foaf:name “Coldplay” http://dbpedia.org/resource/Viva_la_Vida And using these triple expressions, you build up a graph of data...

<http://dbpedia.org/resource/Coldplay> <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> . <http://dbpedia.org/resource/Coldplay> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Band> . ntriples <?xml version="1.0" encoding="utf-8"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <dbpedia-owl:Band xmlns:dbpedia-owl="http://dbpedia.org/ontology/" rdf:about="http://dbpedia.org/resource/Coldplay"> <dbpedia-owl:artist rdf:resource="http://dbpedia.org/resource/Viva_la_Vida"/> </dbpedia-owl:Band> </rdf:RDF> RDF/XML @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . <http://dbpedia.org/resource/Coldplay> a <http://dbpedia.org/ontology/Band> ; <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> . turtle Coming back to RDF, it’s important to note that RDF is a model, a way to describe data - and there are different serialisations of RDF. Here are 2 triples expressed in the ntriples format: it’s the most basic format. You simply get subject - predicate - object - new line, subject - predicate - object - new line Here is the most established RDF format: RDF/XML - unfortunately this is the format most people are exposed to when learning about RDF. It’s horrible to read, it’s ugly - it’s just not user friendly at all! Luckily, there’s turtle: it let’s you write RDF graphs in a compact text format. In turtle, you can see what those 2 triples are saying: The resource here Coldplay, has a type Band, and it’s the artist for this other resource Viva la vida.

Web of Documents Web of Data So RDF and the Web of Data - how does it relate to the web of documents that everyone is familiar with?

http://www.ﬂickr.com/photos/danbri/2415237566/ Actually it’s all the same thing: it’s just the web! There are web documents to be consumed by humans, and there are RDF documents to be consumed by machines, and they live on the web. And these documents describe real objects: people, houses, relationships... And you link from the web documents to the RDF documents... http://www.w3.org/Talks/WWW94Tim/

Content Negotiation A big part of how this all works is content negotiation: when you make an http request you can specify what format you’d prefer the response back, and the server will do it’s best to return stuff in the format you speciﬁed it. So you can say: I’d like this resource about Yves... And if you want RDF, you can ask for

http://dbpedia.org I want to show you what happens when you fetch RDF But ﬁrst I want to introduce DBpedia, as the examples I’ve been showing uses DBpedia URIs.

{{Infobox musical artist | Name = Coldplay | Img = Coldplay - December 2008.jpg | Img_capt = Coldplay, from left to right: {{nowrap| [[Guy Berryman]],}} {{nowrap|[[Jonny Buckland]],}} {{nowrap| [[Chris Martin]],}} and {{nowrap|[[Will Champion]]}} | Img_size = 250 | Landscape = yes | Background = group_or_band | Origin = London, England | Genre = [[Alternative rock]] | Years_active = 1998–present | Label = [[Parlophone Records| Parlophone]]<br>[[Capitol Records|Capitol]]<br>[[Fierce Panda Records|Fierce Panda]] | URL = [http://www.coldplay.com/ coldplay.com] | Current_members = [[Chris Martin]]<br />[[Jonny Buckland]]<br />[[Guy Berryman]]<br />[[Will Champion]] }} http://en.wikipedia.org/wiki/Coldplay http://dbpedia.org/resource/Coldplay The DBpedia project is extracting structured data from Wikipedia, and making it available as Linked Data. It’s mostly based on extracting data from InfoBoxes on the Wikipedia articles. And it uses the Wikipedia article title in the URI for the RDF resource.

Dereference a URI?

http://dbpedia.org/resource/Coldplay

curl --include --location --header "Accept: text/html" http://dbpedia.org/resource/Coldplay HTTP/1.1 303 See Other Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: close Content-Type: text/html; charset=ISO-8859-1 Date: Fri, 23 Oct 2009 14:01:26 GMT Accept-Ranges: bytes Location: http://dbpedia.org/page/Coldplay Content-Length: 0 HTTP/1.1 200 OK Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: Keep-Alive Content-Type: text/html; charset=UTF-8 Date: Fri, 23 Oct 2009 14:01:26 GMT Accept-Ranges: bytes Expires: Sat, 24 Oct 2009 14:01:26 GMT Link: <http://dbpedia.org/data/Coldplay.rdf>; rel="alternate"; title="Metadata in RDF/XML format", <http://dbpedia.org/data/Coldplay.n3>; rel="alternate"; title="Metadata in N3/Turtle format", <http://dbpedia.org/data/Coldplay.json>; rel="alternate"; title="Metadata in JSON+RDF format" Content-Length: 87951 <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml- rdfa-1.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:dbpprop="http://dbpedia.org/property/" xmlns:owl="http://www.w3.org/2002/07/owl#" version="XHTML+RDFa 1.0" xml:lang="en">  <head profile="http://www.w3.org/1999/xhtml/vocab"> <title>About: Coldplay</title>

curl --include --location --header "Accept: application/rdf+xml" http://dbpedia.org/resource/Coldplay HTTP/1.1 303 See Other Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: close Date: Fri, 23 Oct 2009 15:02:52 GMT Accept-Ranges: bytes TCN: choice Vary: negotiate,accept Content-Location: Coldplay.xml Content-Type: application/rdf+xml; qs=0.95 Location: http://dbpedia.org/data/Coldplay.xml Content-Length: 0 HTTP/1.1 200 OK Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: Keep-Alive Date: Fri, 23 Oct 2009 15:02:52 GMT Accept-Ranges: bytes X-SPARQL-default-graph: http%3A%2F%2Fdbpedia.org Content-Type: application/rdf+xml; charset=UTF-8 Content-Length: 81614 <?xml version="1.0" encoding="utf-8" ?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs="http://www.w3.org/ 2000/01/rdf-schema#"> <rdf:Description rdf:about="http://dbpedia.org/resource/Coldplay"><rdfs:label xml:lang="pt">Coldplay</rdfs:label></rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Coldplay"><skos:subject xmlns:skos="http:// www.w3.org/2004/02/skos/core#" rdf:resource="http://dbpedia.org/resource/ Category:English_musical_groups"/></rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Sparks_%28EP%29"><dbpprop:artist xmlns:dbpprop="http://dbpedia.org/property/" rdf:resource="http://dbpedia.org/resource/Coldplay"/></ rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/God_Put_a_Smile_upon_Your_Face"><dbpedia- owl:artist xmlns:dbpedia-owl="http://dbpedia.org/ontology/" rdf:resource="http://dbpedia.org/ resource/Coldplay"/></rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Viva_la_Vida"><dbpedia-owl:band xmlns:dbpedia-owl="http://dbpedia.org/ontology/" rdf:resource="http://dbpedia.org/resource/Coldplay"/ ></rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Coldplay"><rdfs:comment xml:lang="it">I Coldplay sono un gruppo alternative rock britannico. Hanno venduto 50 milioni di dischi in tutto il mondo.</rdfs:comment></rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Lost%21"><dbpedia-owl:band xmlns:dbpedia- owl="http://dbpedia.org/ontology/" rdf:resource="http://dbpedia.org/resource/Coldplay"/></ rdf:Description> <rdf:Description rdf:about="http://dbpedia.org/resource/Coldplay"><dbpprop:commonsCatProperty xmlns:dbpprop="http://dbpedia.org/property/" xml:lang="en">Coldplay</dbpprop:commonsCatProperty></

curl --include --location --header "Accept: text/rdf+n3" http://dbpedia.org/resource/Coldplay HTTP/1.1 303 See Other Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: close Date: Fri, 23 Oct 2009 15:05:56 GMT Accept-Ranges: bytes TCN: choice Vary: negotiate,accept Content-Location: Coldplay.n3 Content-Type: text/rdf+n3; qs=0.8 Location: http://dbpedia.org/data/Coldplay.n3 Content-Length: 0 HTTP/1.1 200 OK Server: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDB Connection: Keep-Alive Date: Fri, 23 Oct 2009 15:05:57 GMT Accept-Ranges: bytes X-SPARQL-default-graph: http%3A%2F%2Fdbpedia.org Content-Type: text/rdf+n3; charset=UTF-8 Content-Length: 42159 @prefix dbpprop: <http://dbpedia.org/property/> . @prefix dbpedia: <http://dbpedia.org/resource/> . <http://dbpedia.org/resource/22_Dreams> dbpprop:after dbpedia:Coldplay . @prefix dbpedia-owl: <http://dbpedia.org/ontology/> . dbpedia:Parachutes dbpedia-owl:artist dbpedia:Coldplay ; dbpprop:artist dbpedia:Coldplay . dbpedia:God_Put_a_Smile_upon_Your_Face dbpedia-owl:band dbpedia:Coldplay ; dbpedia-owl:artist dbpedia:Coldplay ; dbpprop:artist dbpedia:Coldplay . dbpedia:Live_2003 dbpedia-owl:artist dbpedia:Coldplay ; dbpprop:artist dbpedia:Coldplay . <http://dbpedia.org/resource/Safety_%28EP%29> dbpedia-owl:artist dbpedia:Coldplay ;

What’s with the redirection?

http://en.wikipedia.org/wiki/File:MagrittePipe.jpg I think the best way to describe this is using this painting by René Magritte, which shows a pipe but written below is "Ceci n'est pas une pipe" (This is not a pipe). The painting is not a pipe, but rather an image of a pipe. Magritte himself said that of course it was not a pipe, just try to ﬁll it with tobacco.

<http://upload.wikimedia.org/.../coldplay.jpg> Ceci n’est pas Coldplay http://upload.wikimedia.org/wikipedia/commons/e/e1/Coldplay_-_December_2008.jpg So if we extend this to our Coldplay example, this photo is not Coldplay!

About: Coldplay An Entity in Data Space: dbpedia.org 'Coldplayare a British alternative rock band formed in London, England in 1998. Property Value dbpedia-owl:background group_or_band dbpedia-owl:currentMembers dbpedia:Chris_Martin dbpedia:Jonny_Buckland dbpedia:Will_Champion dbpedia:Guy_Berryman dbpedia-owl:genre dbpedia:Alternative_rock dbpedia-owl:label dbpedia:EMI dbpedia:Parlophone_Records dbpedia:Capitol_Records dbpprop:abstract 'Coldplayare a British alternative rock band formed in London, England in 1998. The group comprises vocalist/pian Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, and drummer/backing vocalist/multi-instrumenta Champion. Coldplay has sold 50 million albums, and are also known for their hit singles, such as "Yellow", "The Sc "Clocks", "Speed of Sound", "Fix You" and "Viva la Vida". Coldplay achieved worldwide fame with the release of th "Yellow", followed by their debut album, Parachutes (2000), which was nominated for the Mercury Prize. Its follow- Blood to the Head, won multiple awards such as NMEs Album of the Year. Their next release, X&Y, received a slig enthusiastic yet still generally positive reception. The band's fourth studio album, Viva la Vida or Death and All His produced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and Coldplay's albums have enjoyed commercial success. Coldplay's early material was compared to acts such as Rad Buckley, U2, and Travis. Since the release of Parachutes, Coldplay have drawn influence from other sources, inclu the Bunnymen, Kate Bush and George Harrison on A Rush of Blood to the Head, Johnny Cash and Kraftwerk for X Arcade Fire and My Bloody Valentine on Viva la Vida. Coldplay have been an active supporter of various social an causes, such as Oxfam's Make Trade Fair campaign and Amnesty International. The group have also performed a projects such as Band Aid 20, Live 8, Sound Relief, and the Teenage Cancer Trust. Coldplay er et engelsk band, der i genre svinger imellem pop og let/alternativ rock. Coldplay er af mange udråbt so vigtigste bands i slutningen af 1990'erne og starten af det nye årtusinde, og nogle sammenligner endda deres statu Radiohead og U2. Bandet består af:*Chris Martin: Forsanger, piano, keyboard, guitar *Jon Buckland: Guitar, harmo *Guy Berryman: Bas, synthesizer, harmonika, sang *Will Champion: Trommer/percussion, piano, sangColdplay har været i Danmark. Blandt andet var de et af hovednavnene på Roskilde Festivalen i 2003, i forbindelse med udgive dato, nok mest anerkendte album A Rush of Blood to The Head. Senest de har lagt vejen forbi København var i 20 <http://dbpedia.org/page/Coldplay> Ceci n’est pas Coldplay And this web page from DBpedia is not Coldplay, it’s a web page describing Coldplay!

"2009-05-18T22:36:41+01:00" About: Coldplay An Entity in Data Space: dbpedia.org 'Coldplayare a British alternative rock band formed in London, England in 1998. dcterms:created Property Value dbpedia-owl:background group_or_band dbpedia-owl:currentMembers dbpedia:Chris_Martin dbpedia:Jonny_Buckland dbpedia:Will_Champion dbpedia:Guy_Berryman dbpedia-owl:genre dbpedia:Alternative_rock dbpedia-owl:label dbpedia:EMI dbpedia:Parlophone_Records dbpedia:Capitol_Records dbpprop:abstract 'Coldplayare a British alternative rock band formed in London, England in 1998. The group comprises vocalist/pianist/guitarist Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, and drummer/backing vocalist/multi-instrumentalist Will Champion. Coldplay has sold 50 million albums, and are also known for their hit singles, such as "Yellow", "The Scientist", "Clocks", "Speed of Sound", "Fix You" and "Viva la Vida". Coldplay achieved worldwide fame with the release of their single "Yellow", followed by their debut album, Parachutes (2000), which was nominated for the Mercury Prize. Its follow-up, A Rush of Blood to the Head, won multiple awards such as NMEs Album of the Year. Their next release, X&Y, received a slightly less enthusiastic yet still generally positive reception. The band's fourth studio album, Viva la Vida or Death and All His Friends, was produced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and wins. All of Coldplay's albums have enjoyed commercial success. Coldplay's early material was compared to acts such as Radiohead, Jeff Buckley, U2, and Travis. Since the release of Parachutes, Coldplay have drawn influence from other sources, including Echo and the Bunnymen, Kate Bush and George Harrison on A Rush of Blood to the Head, Johnny Cash and Kraftwerk for X&Y and Blur, Arcade Fire and My Bloody Valentine on Viva la Vida. Coldplay have been an active supporter of various social and political causes, such as Oxfam's Make Trade Fair campaign and Amnesty International. The group have also performed at various charity projects such as Band Aid 20, Live 8, Sound Relief, and the Teenage Cancer Trust. Coldplay er et engelsk band, der i genre svinger imellem pop og let/alternativ rock. Coldplay er af mange udråbt som et af de vigtigste bands i slutningen af 1990'erne og starten af det nye årtusinde, og nogle sammenligner endda deres status med både Radiohead og U2. Bandet består af:*Chris Martin: Forsanger, piano, keyboard, guitar *Jon Buckland: Guitar, harmonika, sang *Guy Berryman: Bas, synthesizer, harmonika, sang *Will Champion: Trommer/percussion, piano, sangColdplay har flere gange været i Danmark. Blandt andet var de et af hovednavnene på Roskilde Festivalen i 2003, i forbindelse med udgivelsen af deres til dato, nok mest anerkendte album A Rush of Blood to The Head. Senest de har lagt vejen forbi København var i 2005 på deres <http://dbpedia.org/page/Coldplay> <http://upload.wikimedia.org/.../coldplay.jpg> foaf:primaryTopic dcterms:created foaf:depiction "2007-05-18T19:31:51+01:00" http://dbpedia.org/resource/Coldplay dbpedia-owl:formed "1998" And it’s important to make this distinction, because it allows us to make different claims about the thing and the documents describing the thing So we want to talk about when Coldplay the band was formed. And for the webpage and the image, we want to say when they were created. And we can link these things together. The page’s primary topic is Coldplay, and the image depicts the Band.

Information Resource Non-Information Resource About: Coldplay An Entity in Data Space: dbpedia.org 'Coldplayare a British alternative rock band formed in London, England in 1998. Property Value dbpedia-owl:background group_or_band dbpedia-owl:currentMembers dbpedia:Chris_Martin dbpedia:Jonny_Buckland dbpedia:Will_Champion dbpedia:Guy_Berryman dbpedia-owl:genre dbpedia:Alternative_rock dbpedia-owl:label dbpedia:EMI dbpedia:Parlophone_Records dbpedia:Capitol_Records dbpprop:abstract 'Coldplayare a British alternative rock band formed in London, England in 1998. The group comprises vocalist/pianist/guitarist Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, and drummer/backing vocalist/multi-instrumentalist Will Champion. Coldplay has sold 50 million albums, and are also known for their hit singles, such as "Yellow", "The Scientist", "Clocks", "Speed of Sound", "Fix You" and "Viva la Vida". Coldplay achieved worldwide fame with the release of their single "Yellow", followed by their debut album, Parachutes (2000), which was nominated for the Mercury Prize. Its follow-up, A Rush of Blood to the Head, won multiple awards such as NMEs Album of the Year. Their next release, X&Y, received a slightly less enthusiastic yet still generally positive reception. The band's fourth studio album, Viva la Vida or Death and All His Friends, was produced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and wins. All of Coldplay's albums have enjoyed commercial success. Coldplay's early material was compared to acts such as Radiohead, Jeff Buckley, U2, and Travis. Since the release of Parachutes, Coldplay have drawn influence from other sources, including Echo and the Bunnymen, Kate Bush and George Harrison on A Rush of Blood to the Head, Johnny Cash and Kraftwerk for X&Y and Blur, Arcade Fire and My Bloody Valentine on Viva la Vida. Coldplay have been an active supporter of various social and political causes, such as Oxfam's Make Trade Fair campaign and Amnesty International. The group have also performed at various charity projects such as Band Aid 20, Live 8, Sound Relief, and the Teenage Cancer Trust. Coldplay er et engelsk band, der i genre svinger imellem pop og let/alternativ rock. Coldplay er af mange udråbt som et af de vigtigste bands i slutningen af 1990'erne og starten af det nye årtusinde, og nogle sammenligner endda deres status med både Radiohead og U2. Bandet består af:*Chris Martin: Forsanger, piano, keyboard, guitar *Jon Buckland: Guitar, harmonika, sang *Guy Berryman: Bas, synthesizer, harmonika, sang *Will Champion: Trommer/percussion, piano, sangColdplay har flere gange været i Danmark. Blandt andet var de et af hovednavnene på Roskilde Festivalen i 2003, i forbindelse med udgivelsen af deres til dato, nok mest anerkendte album A Rush of Blood to The Head. Senest de har lagt vejen forbi København var i 2005 på deres http://dbpedia.org/page/Coldplay http://dbpedia.org/resource/Coldplay http://upload.wikimedia.org/.../coldplay.jpg So there’s a distinction between Information Resources (web documents, images, RDF data) and Non-Information resources, which are the things you can’t send down a wire (people, places, things).

System dereferencing http://dbpedia.org/resource/Coldplay in text/html HTTP GET request (text/html) http://dbpedia.org/resource/Coldplay HTTP 303 response http://dbpedia.org/resource/Coldplay http://dbpedia.org/page/Coldplay time HTTP GET request http://dbpedia.org/page/Coldplay About: Coldplay An Entity in Data Space: dbpedia.org 'Coldplayare a British alternative rock band formed in London, England in 1998. Property Value HTTP 200 response dbpedia-owl:background group_or_band dbpedia-owl:currentMembers dbpedia:Chris_Martin dbpedia:Jonny_Buckland dbpedia:Will_Champion dbpedia:Guy_Berryman dbpedia-owl:genre dbpedia:Alternative_rock dbpedia-owl:label dbpedia:EMI dbpedia:Parlophone_Records dbpedia:Capitol_Records dbpprop:abstract 'Coldplayare a British alternative rock band formed in London, England in 1998. The group comprises vocalist/pianist/guitarist Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, and drummer/backing vocalist/multi-instrumentalist Will HTML data Champion. Coldplay has sold 50 million albums, and are also known for their hit singles, such as "Yellow", "The Scientist", "Clocks", "Speed of Sound", "Fix You" and "Viva la Vida". Coldplay achieved worldwide fame with the release of their single "Yellow", followed by their debut album, Parachutes (2000), which was nominated for the Mercury Prize. Its follow-up, A Rush of Blood to the Head, won multiple awards such as NMEs Album of the Year. Their next release, X&Y, received a slightly less enthusiastic yet still generally positive reception. The band's fourth studio album, Viva la Vida or Death and All His Friends, was produced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and wins. All of Coldplay's albums have enjoyed commercial success. Coldplay's early material was compared to acts such as Radiohead, Jeff Buckley, U2, and Travis. Since the release of Parachutes, Coldplay have drawn influence from other sources, including Echo and the Bunnymen, Kate Bush and George Harrison on A Rush of Blood to the Head, Johnny Cash and Kraftwerk for X&Y and Blur, Arcade Fire and My Bloody Valentine on Viva la Vida. Coldplay have been an active supporter of various social and political causes, such as Oxfam's Make Trade Fair campaign and Amnesty International. The group have also performed at various charity projects such as Band Aid 20, Live 8, Sound Relief, and the Teenage Cancer Trust. Coldplay er et engelsk band, der i genre svinger imellem pop og let/alternativ rock. Coldplay er af mange udråbt som et af de vigtigste bands i slutningen af 1990'erne og starten af det nye årtusinde, og nogle sammenligner endda deres status med både Radiohead og U2. Bandet består af:*Chris Martin: Forsanger, piano, keyboard, guitar *Jon Buckland: Guitar, harmonika, sang *Guy Berryman: Bas, synthesizer, harmonika, sang *Will Champion: Trommer/percussion, piano, sangColdplay har flere gange været i Danmark. Blandt andet var de et af hovednavnene på Roskilde Festivalen i 2003, i forbindelse med udgivelsen af deres til dato, nok mest anerkendte album A Rush of Blood to The Head. Senest de har lagt vejen forbi København var i 2005 på deres

System dereferencing http://dbpedia.org/resource/Coldplay in application/rdf+xml HTTP GET request (application/rdf+xml) http://dbpedia.org/resource/Coldplay HTTP 303 response http://dbpedia.org/resource/Coldplay http://dbpedia.org/data/Coldplay.xml time HTTP GET request http://dbpedia.org/data/Coldplay.xml <rdf/> HTTP 200 response describing RDF data Coldlay

http://www.bbc.co.uk/music/artists/:id http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234 Text only Help Search Explore the BBC QUICK FIND Enter an artist name ... BBC Music Artists Coldplay Coldplay Group. Formed September 1996. Played By Since December 2008 1. Greg James BBC Radio 1 2. Edith Bowman BBC Radio 1 3. Latest News Stories NEWS FROM THE BBC Chris Hawkins BBC 6 Music Simon Pegg plays with Coldplay Sat 19 Sep 2009 15:24 Actor Simon Pegg joins Coldplay on stage at Wembley Stadium on Friday night at the... 4. No change for Girls' Coldplay set Thu 17 Sep 2009 14:10 Girls Aloud say they will not make any concessions to rock fans when they support... Scott Mills Coldplay copyright case 'settled' BBC Radio 1 Wed 16 Sep 2009 13:27 Coldplay and Joe Satriani reach agreement over a court case alleging

http://www.bbc.co.uk/music/artists/:id.rdf http://www.bbc.co.uk/music/artists/:id#artist @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix owl: <http://www.w3.org/2002/07/owl#> . @prefix mo: <http://purl.org/ontology/mo/> . @prefix foaf: <http://xmlns.com/foaf/0.1/> . <http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5- d52ba2e14234.rdf> rdfs:label "Description of the artist Coldplay" ; foaf:primaryTopic <http://www.bbc.co.uk/music/artists/cc197bad- dc9c-440d-a5b5-d52ba2e14234#artist> . <http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5- d52ba2e14234#artist> a mo:MusicArtist, mo:MusicGroup ; foaf:name "Coldplay" ; owl:sameAs <http://dbpedia.org/resource/Coldplay> ; foaf:page <http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d- a5b5-d52ba2e14234.html> . We can also use Hash URIs to refer to non-information resource.

System dereferencing http://dbpedia.org/resource/Coldplay in text/html HTTP GET request (text/html) http://www.bbc.co.uk/music/artists/:id#artist <html/> time HTTP 200 response describing HTML Data Coldplay

System dereferencing http://dbpedia.org/resource/Coldplay in application/rdf+xml HTTP GET request (application/rdf+xml) http://www.bbc.co.uk/music/artists/:id#artist <rdf/> time HTTP 200 response describing RDF Data Coldplay

RDFa <html> ... <div xmlns:dc="http://purl.org/dc/elements/1.1/"> <h2 property="dc:title">The trouble with Bob</h2> <h3 property="dc:creator">Alice</h3> ... </div> ... </html> A further option is to use RDFa, where RDF is embedded into the HTML markup directly.

System dereferencing http://dbpedia.org/resource/Coldplay in RDFa HTTP GET request http://www.bbc.co.uk/music/artists/:id <html+rdf> time HTTP 200 response describing HTML + RDF Data Coldplay

Let’s consume some RDF! rapper Rapper is a tool for parsing RDF data and outputting in different formats.

rapper http://dbpedia.org/resource/Coldplay => returns triples e.g. <http://dbpedia.org/resource/Coldplay> <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> . So when we run rapper on a Linked Data URI we get back triples, e.g.

<http://dbpedia.org/resource/Coldplay> <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> . rapper -oturtle http://dbpedia.org/ontology/artist => returns data formatted in turtle @prefix owl: <http://www.w3.org/2002/07/owl#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . <http://dbpedia.org/ontology/artist> a owl:ObjectProperty ; rdfs:label "artist" . And if everything is linked data, then we can go and dereference the property and ﬁnd out more about it: e.g. there’s a human readable label for this property you can use in your application.

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . <http://dbpedia.org/resource/Coldplay> a <http://dbpedia.org/ontology/Band> ; <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> . <http://dbpedia.org/ontology/Band> <http://dbpedia.org/ontology/artist> And coming back to the data about an artist, you can see how there are these special URIs that are let you describe what the resource is. * So there is this URI that says Coldplay is a band * And this URI is the property we saw earlier, it says an artist created a record. You can deﬁne vocabularies and ontologies that allow you to describe a speciﬁc domain.

Vocabularies and Ontologies • people • social media • commerce • events • radio and tv programmes • music • etc And there are plenty of vocabularies available out there that can be used.

owl:sameAs http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist = http://dbpedia.org/resource/Coldplay = http://dbtune.org/musicbrainz/resource/artist/cc197bad-dc9c-440d-a5b5-d52ba2e14234 = http://dbtune.org/myspace/coldplay = http://lastfm.rdﬁze.com/artists/Coldplay Just want to quickly mention one property of the Web Ontology Language that comes up a lot in Linked Data discussions: the owl:sameAs property. It allows us to declare that non-information resources across the web are the same thing So the BBC's Coldplay is the same as... • ...the DBpedia Coldplay is the same as... • ...the MusicBrainz Coldplay is the same as... • ...the Myspace Coldplay is the same as... • ...the last.fm New Order is the same as... • ...etc And this makes it possible to aggregate data about a particular thing from different sources really easily.

Consuming BBC Linked Data using Tabulator http://moustaki.org/resources/screencast-music.ogv

Consuming linked data by machines

by Patrick Sinclair

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Consuming linked data by machines Document Transcript