Getting
Started
Issues people have when they want to start
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Getting Started
Finding URIs
Finding Additional Data
Finding SPARQL Endpoints
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
● Problem: What URIs exist that identify the thing
I'm interested in?
● Two options:
● Data source specific solutions
● Search engines for the Web of Linked Data
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
● Some Linked Data sources provide a keyword-
based search for things in their dataset(s)
● RKB Explorer http://www.rkbexplorer.com/
● DBpedia http://lookup.dbpedia.org/
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
● What if there is no search possibility?
● You may try a SPARQL query:
SELECT DISTINCT ?s WHERE {
?s rdfs:label ?label .
FILTER regex( str(?label), "Berlin", "i" ) .
}
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
● Search engines for the Web of Linked Data
provide keyword-based search for things in
different datasets
● Falcons http://iws.seu.edu.cn/services/falcons/
● Sindice http://sindice.com
● SWSE http://www.swse.org
● Watson http://watson.kmi.open.ac.uk
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding URIs
● There are also APIs
● Falcons
http://iws.seu.edu.cn/services/falcons/api/index.jsp
● Sindice
http://sindice.com/developers/api
● Watson
http://watson.kmi.open.ac.uk/REST_API.html
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<foaf:Document
rdf:about="http://iws.seu.edu.cn/services/falcons/api/objectsearch.jsp?query=Berlin">
<dc:description>Provides at most 10 objects hit by the query Berlin.</dc:description>
<dc:title>Objects hit by the query Berlin</dc:title>
<dc:creator>Falcons API</dc:creator>
</foaf:Document>
<rdf:Seq>
<rdf:li rdf:resource="http://dbpedia.org/resource/Berlin"/>
<rdf:li rdf:resource="http://dbpedia.org/resource/Category:Berlin"/>
<rdf:li rdf:resource="http://dbpedia.org/resource/Category:People_from_Berlin"/>
<rdf:li rdf:resource="http://www.deadjournal.com/interests.bml?int=berlin"/>
<rdf:li rdf:resource="http://dbtune.org/jamendo/tag/berlin"/>
<rdf:li rdf:resource="http://www4.wiwiss.fu-berlin.de/bookmashup/subject/Berlin"/>
<rdf:li rdf:resource="http://www.liveinternet.ru/journal_interest.php?interestid=51320"/>
<rdf:li rdf:resource="http://wiki.sembase.at/index.php/_Berlin"/>
<rdf:li rdf:resource="http://dbpedia.org/resource/Category:Berlin_U-Bahn_stations"/>
<rdf:li rdf:resource="http://dbpedia.org/resource/Category:Berlin_culture"/>
</rdf:Seq>
</rdf:RDF>
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Getting Started
Finding URIs
Finding Additional Data
Finding SPARQL Endpoints
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding Additional Data
● Problem: Given a URI, where do I find
more data as what is available
by looking it up?
● Three options:
● Follow links (e.g. rdfs:seeAlso, owl:sameAs)
● Use a co-reference service
● Use a search engine for the Web of Linked Data
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding Additional Data
● Co-reference services find different URIs that
refer to the same thing
● sameAs http://sameas.org
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding Additional Data
● There is also an API
● Specify the preferred format in the URI
http://sameas.org/rdf?uri=http://dbpedia.org/resource/Berlin
http://sameas.org/n3?uri=http://dbpedia.org/resource/Berlin
http://sameas.org/json?uri=http://dbpedia.org/resource/Berlin
● Use content negotiation
GET /?uri=http://dbpedia.org/... HTTP/1.1
Host: sameas.org
Accept: application/rdf+xml
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding Additional Data
● Search engines for the Web of Linked Data
provide URI-based search for data from
different sources
● Sindice http://sindice.com
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Getting Started
Finding URIs
Finding Additional Data
Finding SPARQL Endpoints
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"

Finding SPARQL Endpoints
● Look at:
http://esw.w3.org/topic/SparqlEndpoints
● SPARQL 1.1 Service Description
● Vocabulary of Interlinked Datasets (voiD)
ISWC 2009 Tutorial "How to Consume Linked Data on the Web"