Download - Creating Linked Data
![Page 1: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/1.jpg)
Creating Linked Data
Juan F. SequedaSemantic Technology Conference
June 2011
![Page 2: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/2.jpg)
Linked Data is a set of best practices to publish and interlink data
on the web
![Page 3: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/3.jpg)
Linked Data Principles1. Use URIs as names for
things2. Use HTTP URIs so that
people can look up (dereference) those names.
3. When someone looks up a URI, provide useful information.
4. Include links to other URIs so that they can discover more things.
![Page 4: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/4.jpg)
1) Use URIs as names for things
![Page 5: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/5.jpg)
1) Use URIs as names for things
• Uniform Resource Identifiers identify real world objects and abstract concepts– Not only web documents and digital content– People, places, locations, my car– Know somebody, from somewhere
![Page 6: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/6.jpg)
1) Use URIs as names for things
http://juansequeda.com/foaf.rdf#me http://www.w3.org/People/Berners-Lee/card#i
http://xmlns.com/foaf/0.1/knows
![Page 7: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/7.jpg)
1) Use URIs as names for things
• http://juansequeda.com/foaf.rdf#me– Identifies the person
• http://juansequeda.com/foaf.rdf– Identifies an RDF document
![Page 8: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/8.jpg)
2) Use HTTP URIs so that people can look up (dereference) those names.
![Page 9: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/9.jpg)
2) Use HTTP URIs so that people can look up (dereference) those names.
• HTTP protocol is the Web’s universal access mechanism
• Linked Data only uses HTTP URIs– URI: unique name– HTTP URI: universal means of access to the URI
• HTTP URIs should be dereferencable
![Page 10: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/10.jpg)
Dereference a URI?
![Page 11: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/11.jpg)
![Page 12: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/12.jpg)
![Page 13: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/13.jpg)
![Page 14: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/14.jpg)
![Page 15: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/15.jpg)
![Page 16: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/16.jpg)
What’s with the redirection?
![Page 17: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/17.jpg)
![Page 18: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/18.jpg)
![Page 19: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/19.jpg)
![Page 20: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/20.jpg)
![Page 21: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/21.jpg)
![Page 22: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/22.jpg)
![Page 23: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/23.jpg)
![Page 24: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/24.jpg)
![Page 25: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/25.jpg)
![Page 26: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/26.jpg)
![Page 27: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/27.jpg)
![Page 28: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/28.jpg)
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>
![Page 29: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/29.jpg)
![Page 30: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/30.jpg)
Minting HTTP URIs
• If you own the domain name and run a web server at that location, mint URIs in this namespace
• I own the domain mycompany.com• I run a webserver http://mycompany.com• I now can mint URIs in this namespace:– http://mycompany.com/person/Juan-Sequeda
![Page 31: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/31.jpg)
Create Cool URIs
• If you don’t control a namespace, don’t misuse it– http://www.imdb.com/title
• Avoid implementation details– http://foo.mycompany.com:8080/person.php?id=
123&format=rdf• Use Natural Keys within URI– http://mycompany.com/person/Juan-Sequeda– http://mycompany.com/person/123
![Page 32: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/32.jpg)
Three different URIs• URI for the real world object (non-information resource)
– http://dbpedia.org/resource/London– http://id.mycompany.com/person/Juan-Sequeda– http://mycompany.com/person/Juan-Sequeda– http://www.juansequeda.com/foaf.rdf#me
• URI for the HTML document (information resource) that describes the real world object– http://dbpedia.org/page/London– http://pages.mycompany.com/person/Juan-Sequeda– http://mycompany.com/person/Juan-Sequeda.html
• URI for the RDF document (information resource) that describes the real world object– http://dbpedia.org/data/London– http://data.mycompany.com/Juan-Sequeda– http://mycompany.com/person/Juan-Sequeda.rdf– http://www.juansequeda.com/foaf.rdf
![Page 33: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/33.jpg)
3) Provide useful information
![Page 34: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/34.jpg)
3) Provide useful information
• How do we provide useful information in document form on the web? HTML
• How do we provide useful information in data form on the web RDF
• Different ways of serializing RDF– RDF/XML– RDFa– N3– turtle
![Page 35: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/35.jpg)
RDFsubject – predicate – object
Coldplay is the artist of Viva la VidaColdplay is the artist of Viva la Vida
http://dbpedia.org/resource/Coldplay
http://dbpedia.org/resource/Viva_la_Vida
http://dbpedia.org/ontology/artist
![Page 36: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/36.jpg)
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#>
http://dbpedia.org/resource/Coldplay
http://dbpedia.org/resource/Viva_la_Vida
http://dbpedia.org/resource/London
dbpedia-owl:artist foaf:name
dbprop:origin
geo:longgeo:lat
“Coldplay”
51.507778-0.128056
![Page 37: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/37.jpg)
<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> .
<?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>
@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> .
ntriples
RDF/XML
turtle
![Page 38: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/38.jpg)
HTML
<div>My name is Bob Smith, but people call me Smithy. Here is my home page:<a href="http://www.example.com">www.example.com</a>.I live in Albuquerque, NM and work as an engineer at ACME Corp.My friends:<a href="http://darryl-blog.example.com">Darryl</a>,<a href="http://edna-blog.example.com">Edna</a></div>
![Page 39: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/39.jpg)
RDFa (RDF in HTML)<div xmlns:v="http://rdf.data-vocabulary.org/#" typeof="v:Person"> My name is <span property="v:name">Bob Smith</span>, but people call me <span property="v:nickname">Smithy</span>. Here is my homepage: <a href="http://www.example.com" rel="v:url">www.example.com</a>. I live in <span rel="v:address"> <span typeof="v:Address"> <span property="v:locality">Albuquerque</span>, <span property="v:region">NM</span> </span> </span> and work as an <span property="v:title">engineer</span> at <span property="v:affiliation">ACME Corp</span>. My friends: <a href="http://darryl-blog.example.com" rel="v:friend">Darryl</a>, <a href="http://edna-blog.example.com" rel="v:friend">Edna</a></div>
![Page 40: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/40.jpg)
What to publish?
• Literal Triples<http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist>
<foaf:name> “Coldplay”
• Outgoing Links<http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist>
<owl:sameAs> <http://dbpedia.org/resource/Coldplay>
• Incoming Link<http://www.bbc.co.uk/music/artists/18690715-59fa-4e4d-bcf3-8025cf1c23e0#artist>
<mo:member_of> <http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist>
![Page 41: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/41.jpg)
What to publish?
• Description of the data set– Semantic Sitemaps– voiD (Vocabulary of Interlinked Datasets)
• Provenance Metadata• Licenses Information
![Page 42: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/42.jpg)
Vocabularies (or Schemas or Ontologies)
• Create your own using– Simple Knowledge Organization Systems (SKOS)• Taxonomy
– RDF Vocabulary Description Language (RDF Schema)• Light weight vocabularies
– Web Ontological Language (OWL)• Highly expressive and capable of inferencing
![Page 43: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/43.jpg)
Vocabularies (or Schemas or Ontologies)
• Reuse vocabularies– Dublin Core: metadata attributes– Friend of a Friend (FOAF): persons and relationships– Semantically Interlinked Online Communities (SIOC):
describing users, posts, blogs, etc– Description of a Project (DOAP)– Music Ontology– Programmes Ontology: TV and radio programs– Good Relations: describing products and services– Review Vocabulary– Basic Geo (WGS84) Vocabulary
![Page 44: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/44.jpg)
4) Include links to other things
![Page 45: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/45.jpg)
4) Include links to other things
• Set external RDF links into other data sources on the Web– Subject of the triple is in the namespace of one
data set– Object of the triple is a URI in the namespace of
another data set• Connect siloed data islands• Enable discovery
![Page 46: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/46.jpg)
4) Include links to other things
• Relationship Links<http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist> <http://xmlns.com/foaf/0.1/based_near>
<http://dbpedia.org/resource/London>
• Identity Link<http://www.bbc.co.uk/music/artists/cc197bad-dc9c-440d-a5b5-d52ba2e14234#artist>
<http://www.w3.org/2002/07/owl#sameAs><http://dbpedia.org/resource/Coldplay>
• Vocabulary Links<http://purl.org/ontology/mo/image>
<http://www.w3.org/2000/01/rdf-schema#subPropertyOf><http://xmlns.com/foaf/0.1/depiction>
![Page 47: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/47.jpg)
Which predicate for linking to choose?
• Depends on your domain• Is it widely used?– owl:sameAs– foaf:knows– foaf:based_near– …
• If you create your own, relate it to a widely used predicate
![Page 48: Creating Linked Data](https://reader036.vdocuments.net/reader036/viewer/2022070500/568168d5550346895ddfca62/html5/thumbnails/48.jpg)
How to create the links?
• Manually– Works for small and static data sets– I want to find another URI that identifies the same
real object that I have• Sindice and Falcons provide index of URIs by keyword
• (Semi) Automatic– Record Linkage/Identity Resolution/Co-reference– Silk: http://www4.wiwiss.fu-berlin.de/bizer/silk/– LIMES: http://aksw.org/Projects/limes