Consuming linked data by machines

Consuming Linked Data by Machines

Consuming Linked Data TutorialISWC 2009, Washington DC

Patrick Sinclair, BBC

http://consuminglinkeddata.org/

http://consuminglinkeddata.org/

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.

RDFsubject - 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/resource/Viva_la_Vida

http://dbpedia.org/ontology/artist

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.








dbpedia-owl:artist


prefix dbpedia-owl: <http://dbpedia.org/ontology/>

foaf:name“Coldplay”

dbprop:origin

http://dbpedia.org/resource/London

geo:lat geo:long

51.507778 -0.128056

prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>

prefix foaf: <http://xmlns.com/foaf/0.1/>prefix dbprop: <http://dbpedia.org/property/>

And using these triple expressions, you build up a graph of data...







http://xmlns.com/foaf/0.1/name

http://xmlns.com/foaf/0.1/name



http://dbpedia.org/property/origin

http://dbpedia.org/property/origin

<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/

http://www.flickr.com/photos/danbri/2415237566/

http://www.flickr.com/photos/danbri/2415237566/

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 RDFBut first I want to introduce DBpedia, as the examples I’ve been showing uses DBpedia URIs.

http://dbpedia.org

http://dbpedia.org

http://en.wikipedia.org/wiki/Coldplayhttp://dbpedia.org/resource/Coldplay

{{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]]}}

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.

http://en.wikipedia.org/wiki/Coldplay

http://en.wikipedia.org/wiki/Coldplay



http://www.coldplay.com

http://www.coldplay.com

Dereference a URI?


curl --include --location --header "Accept: text/html" http://dbpedia.org/resource/Coldplay

HTTP/1.1 200 OKServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: Keep-AliveContent-Type: text/html; charset=UTF-8Date: Fri, 23 Oct 2009 14:01:26 GMTAccept-Ranges: bytesExpires: Sat, 24 Oct 2009 14:01:26 GMTLink: <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>

HTTP/1.1 303 See OtherServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: closeContent-Type: text/html; charset=ISO-8859-1Date: Fri, 23 Oct 2009 14:01:26 GMTAccept-Ranges: bytesLocation: http://dbpedia.org/page/ColdplayContent-Length: 0

http://www.w3.org/2002/07/owl#

http://www.w3.org/2002/07/owl#

http://www.w3.org/1999/xhtml/vocab

http://www.w3.org/1999/xhtml/vocab

curl --include --location --header "Accept: application/rdf+xml" http://dbpedia.org/resource/Coldplay

HTTP/1.1 303 See OtherServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: closeDate: Fri, 23 Oct 2009 15:02:52 GMTAccept-Ranges: bytesTCN: choiceVary: negotiate,acceptContent-Location: Coldplay.xmlContent-Type: application/rdf+xml; qs=0.95Location: http://dbpedia.org/data/Coldplay.xmlContent-Length: 0

HTTP/1.1 200 OKServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: Keep-AliveDate: Fri, 23 Oct 2009 15:02:52 GMTAccept-Ranges: bytesX-SPARQL-default-graph: http%3A%2F%2Fdbpedia.orgContent-Type: application/rdf+xml; charset=UTF-8Content-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></rdf:Description><rdf:Description rdf:about="http://dbpedia.org/resource/Gravity_%28Embrace_song%29"><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/X%26Y"><dbpedia-owl:artist xmlns:dbpedia-owl="http://dbpedia.org/ontology/" rdf:resource="http://dbpedia.org/resource/Coldplay"/></rdf:Description>

http://www.w3.org/1999/02/22-rdf-syntax-ns#


http://www.w3.org/2000/01/rdf-schema#








http://www.w3.org/2004/02/skos/core#




http://dbpedia.org/resource/Category:English_musical_groups




http://dbpedia.org/resource/Sparks_%28EP%29

http://dbpedia.org/resource/Sparks_%28EP%29

http://dbpedia.org/property/




http://dbpedia.org/resource/God_Put_a_Smile_upon_Your_Face

http://dbpedia.org/resource/God_Put_a_Smile_upon_Your_Face

http://dbpedia.org/ontology/














http://dbpedia.org/resource/Lost%21

http://dbpedia.org/resource/Lost%21









curl --include --location --header "Accept: text/rdf+n3" http://dbpedia.org/resource/Coldplay

HTTP/1.1 303 See OtherServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: closeDate: Fri, 23 Oct 2009 15:05:56 GMTAccept-Ranges: bytesTCN: choiceVary: negotiate,acceptContent-Location: Coldplay.n3Content-Type: text/rdf+n3; qs=0.8Location: http://dbpedia.org/data/Coldplay.n3Content-Length: 0

HTTP/1.1 200 OKServer: Virtuoso/06.00.3123 (Solaris) x86_64-sun-solaris2.10-64 VDBConnection: Keep-AliveDate: Fri, 23 Oct 2009 15:05:57 GMTAccept-Ranges: bytesX-SPARQL-default-graph: http%3A%2F%2Fdbpedia.orgContent-Type: text/rdf+n3; charset=UTF-8Content-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 ;



http://dbpedia.org/resource/

http://dbpedia.org/resource/

http://dbpedia.org/resource/22_Dreams

http://dbpedia.org/resource/22_Dreams



http://dbpedia.org/resource/Safety_%28EP%29

http://dbpedia.org/resource/Safety_%28EP%29

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.

Ceci n’est pas Coldplay

<http://upload.wikimedia.org/.../coldplay.jpg>

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: ColdplayAn 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_Martindbpedia:Jonny_Bucklanddbpedia:Will_Championdbpedia:Guy_Berryman

dbpedia-owl:genre dbpedia:Alternative_rock

dbpedia-owl:label dbpedia:EMIdbpedia:Parlophone_Recordsdbpedia:Capitol_Records

dbpprop:abstract 'Coldplayare a British alternative rock band formed in London, England in 1998. The group comprises vocalist/pianist/guitaristChris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, and drummer/backing vocalist/multi-instrumentalist WillChampion. 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 ofBlood to the Head, won multiple awards such as NMEs Album of the Year. Their next release, X&Y, received a slightly lessenthusiastic yet still generally positive reception. The band's fourth studio album, Viva la Vida or Death and All His Friends, wasproduced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and wins. All ofColdplay's albums have enjoyed commercial success. Coldplay's early material was compared to acts such as Radiohead, JeffBuckley, U2, and Travis. Since the release of Parachutes, Coldplay have drawn influence from other sources, including Echo andthe 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 politicalcauses, such as Oxfam's Make Trade Fair campaign and Amnesty International. The group have also performed at various charityprojects 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 devigtigste bands i slutningen af 1990'erne og starten af det nye årtusinde, og nogle sammenligner endda deres status med bådeRadiohead 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 gangeværet i Danmark. Blandt andet var de et af hovednavnene på Roskilde Festivalen i 2003, i forbindelse med udgivelsen af deres tildato, 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>

Ceci n’est pas ColdplayAnd this web page from DBpedia is not Coldplay, it’s a web page describing Coldplay!

http://dbpedia.org/page/Coldplay




Property Value






<http://dbpedia.org/page/Coldplay>


<http://upload.wikimedia.org/.../coldplay.jpg>foaf:primaryTopic

foaf:depiction

dcterms:created

"2009-05-18T22:36:41+01:00"

dcterms:created

"2007-05-18T19:31:51+01:00"

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.



http://upload.wikimedia.org/.../coldplay.jpg


Information Resource Non-Information Resource



Property Value









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 303 responsehttp://dbpedia.org/page/Coldplay

HTTP 200 responseHTML data

timeHTTP GET request

http://dbpedia.org/page/Coldplay About: ColdplayAn Entity in Data Space: dbpedia.org


Property Value






HTTP GET request (text/html)http://dbpedia.org/resource/Coldplay




in application/rdf+xml

HTTP 303 responsehttp://dbpedia.org/data/Coldplay.xml

HTTP 200 responseRDF data

HTTP GET requesthttp://dbpedia.org/data/Coldplay.xml

<rdf/> describing Coldlay

time

HTTP GET request (application/rdf+xml)




BBC Music Artists Coldplay

NEWS FROM THE BBC

Simon Pegg plays with ColdplaySat 19 Sep 2009 15:24 Actor Simon Pegg joins Coldplay on stage at Wembley Stadium onFriday night at the...

No change for Girls' Coldplay setThu 17 Sep 2009 14:10 Girls Aloud say they will not make any concessions to rock fans whenthey support...

Coldplay copyright case 'settled'Wed 16 Sep 2009 13:27 Coldplay and Joe Satriani reach agreement over a court case alleging

Since December 2008

QUICK FIND Enter an artist name ...

ColdplayGroup. Formed September 1996.

Latest News Stories

Played By

1.

Greg James

BBC Radio 1

2.

Edith Bowman

BBC Radio 1

3.

Chris Hawkins

BBC 6 Music

4.

Scott Mills

BBC Radio 1

Text only Help Search Explore the BBC

http://www.bbc.co.uk/music/artists/:id http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234

http://www.bbc.co.uk/music/artists/:id.rdf

@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> .

http://www.bbc.co.uk/music/artists/:id#artist

We can also use Hash URIs to refer to non-information resource.

http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234.rdf



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.html





in text/html

HTTP 200 responseHTML Data

time

HTTP GET request (text/html)http://www.bbc.co.uk/music/artists/:id#artist

<html/> describing Coldplay


in application/rdf+xml

HTTP GET request (application/rdf+xml)

http://www.bbc.co.uk/music/artists/:id#artist

HTTP 200 responseRDF Data

time<rdf/>

describing Coldplay

<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>

RDFa

A further option is to use RDFa, where RDF is embedded into the HTML markup directly.

http://purl.org/dc/elements/1.1/

http://purl.org/dc/elements/1.1/


in RDFa

HTTP 200 responseHTML + RDF Data

time

HTTP GET requesthttp://www.bbc.co.uk/music/artists/:id

<html+rdf> describing 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.







@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" .

rapper -oturtle http://dbpedia.org/ontology/artist

=> returns data formatted in turtle

<http://dbpedia.org/resource/Coldplay> <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/Viva_la_Vida> .

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.





http://dbpedia.org/property/designer

http://dbpedia.org/property/designer

@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.

http://dbpedia.org/ontology/Band

http://dbpedia.org/ontology/Band



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://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.



http://dbtune.org/musicbrainz/resource/artist/79239441-bfd5-4981-a70c-55c3f15c1287

http://dbtune.org/musicbrainz/resource/artist/79239441-bfd5-4981-a70c-55c3f15c1287





Consuming BBC Linked Data using Tabulator

http://moustaki.org/resources/screencast-music.ogv

Consuming linked data by machines

Technology

rdf documents

rdf resource

coldplay http

vida http

established rdf format

rdf graphs

prefix rdf

rdf subject predicate