the social semantic web and linked data

Digital Enterprise Research Institute www.deri.ie

The Social Semantic Weband

Linked Data

DM110 Emerging Web Media10th November 2008

Alexandre Passant <alexandre.passant@deri.org>Digital Enterprise Research Institute, National University of Ireland, Galway

Agenda

Issues of Web 2.0 websites Data portability, lack of semantics ... Social network fatigue

The Social Semantic Web FOAF, SIOC Exporting Data, unifying identities ...

Linked Data The Linking Open Data initiative DBpedia Queries examples (hands on)

Conclusion And references

Web 2.0: What if I want to ...

Move my content from one place to another ? RSS ? Not enough

Aggregate my data An open FriendFeed ?

Re-use my Flickr friends on Twitter ? Invite. Again and again ...

The Semantic Web can help ! By providing a common framework to interlink data from

various providers in an open way But what about Web economy ?

So may social media sites ...

* Source: Smashcut Media, www.smashcut-media.com

So may social media sites ...

* Source: Smashcut Media, www.smashcut-media.com

Even more services…

It takes a lot of time…

Filling out profiles, re-adding your friends…

Uploading content to “stovepipes”!

Social media sites are like data silos

* Source: Pidgin Technologies, www.pidgintech.com

Many isolated communities of users and their data

Need ways to connect these islands

Allowing users to easily move from one to another

Enabling users to easily bring their data with them

Solving the issues

Social Network Fatigue “People are getting sick of registering and re-declaring their friends

on every site” Brad Fitzpatrick (Aug. 2007)

The Social Semantic Web Combining Web 2.0 and the Semantic Web Enabling a distributed graph of people, networks and content “I think we could have both Semantic Web technology

supporting online communities, but at the same time also online communities can support Semantic Web data by being the sources of people voluntarily connecting things together.” Tim Berners-Lee (ISWC2005 podcast)

Social Semantic Information Spaces

Introducing FOAF and SIOC

Describing people and their relationships FOAF - Friend Of A FRiend http://foaf-project.org

Describing Social Media Contributions (CMS) SIOC - Semantically-Interlinked Online Communities http://sioc-project.org

FOAF and SIOC are strongly related Interlinking both to represent the complete online activity of

one person More details later

Modeling people with FOAF

FOAF is the main vocabulary used to represent people Friend Of A Friend - http://foaf-project.org

foaf:Person class: “The foaf:Person class represents people. Something is a

foaf:Person if it is a person.” Give yourself a URI

http://apassant.net/alex

Various properties to model your identity :Alex rdf:type foaf:Person ;

foaf:name “Alexandre Passant” ; foaf:mbox “alex@passant.org” .

Relationships using the foaf:knows property: :John foaf:knows :Alex

Extending relationships

foaf:knows is voluntary broad No difference between friends, collegues, family members ...

The RELATIONSHIP vocabulary http://vocab.org/relationship/

More than 30 different kinds of relationships :John rel:worksWith :Alex . :Alice rel:engagedTo :Bob .

All rel:* properties are subproperties of foaf:knows RDFS inferencing allows tools to answer queries using

foaf:knows when people use rel:* alternatives

Integrating social networks w/ FOAF

Source: Sheila Kinsella, Applications of Social Network Analysis 2007

Common formats,unique URIsSource: Sheila Kinsella, Applications of Social Network Analysis 2007

FOAF from existing data

Existing FOAF exporters for major Web 2.0 services Flickr, Facebook, Twitter ...

– http://apassant.net/home/2007/12/flickrdf/– http://www.dcs.shef.ac.uk/~mrowe/foafgenerator.html– http://tools.opiumfield.com/twitter/username–

Unifying Web 2.0 networks

Unified queries

Using SPARQL No matter where the data comes from, as soon as it is

exported via FOAF in RDF SELECT ?f1 ?f2

WHERE {

?f1 foaf:knows ?f2 .

} {Alice, Bob} {Bob, Alex} {Alex, Bob}

:Alice

foaf:knows

foaf:name

Distributed identity management

A need to unify URIs from different services so as to represent one's unified identity Unifying aspects of a foaf:Person across networks:

Linked-data principles : owl:sameAs + rdfs:seeAlso: owl:sameAs: Used to identify two resources with different

URIs as being the same resource– :alex owlSameAs flickr:33669349@N00 .

rdfs:seeAlso: “More information about this resource can be found here”, can be used by Semantic Web browsers

Inference using owl:InverseFunctionalProperty: foaf:mbox, foaf:openid, etc. can be used to identify

uniqueness for a foaf:Person

Unifying networks

Browsing FOAF data

FOAFnaut, FOAF Explorer, FOAFmap, etc ... FOAFGear: thanks to common semantics, only 100

lines of code: http://apassant.net/home/2008/01/foafgear/

More tools and services

Browse / re-use your social graph in personal applications

Tools: Beatnik - https://sommer.dev.java.net/AddressBook.html Knowee - http://knowee.org SPARQLpress - http://wiki.foaf-project.org/SparqlPress Nepomuk - http://nepomuk.semanticdesktop.org/

Social Media Contributions

Lots of user-created content posted on the Web: Blog posts, wiki pages, bulletin board threads Called « Social Media Contributions » or SMC

Distributed content Blogging platform, photos-sharing website, social

bookmarking service ….

A need for common semantics to Provide a single model for any SMC, wherever it comes

from Enables the use of SPARQL queries instead of proprietary

APIs Interlink data and find relationships between content From documents to resources, from WWW to GGG

Modeling SMC on the Semantic Web

SIOC - Semantically Interlinked Online Communities http://sioc-project.org

A ontology to represent the activities of online communities on the Web More than 40 applications, mainly open-source

W3C Member Submission, June 2007 http://www.w3.org/Submission/2007/02/

The SIOC food chain

The SIOC Ontology

Namespace - http://rdfs.org/sioc/ns Five top-level classes: User / Role / Space / Container /

A “SIOC Types” module for Social Web content http://rdfs.org/sioc/types

Actions: A user posts an item in a container :Alex sioc:creator_of <http://example.org/blogpost> .

A Semantic Web citizen: Reusing and interlinking existing ontologies Not reinventing the wheel (connects to DC, FOAF, etc.): http://www.w3.org/Submission/2007/SUBM-sioc-related-20070612/

The SIOC Ontology

Sample export of SIOC data from vBulletin

Connecting people and accounts

The sioc:User class: Can be thought of as a virtual representation of any

person online, within the context of a given social media website or community

A subclass of foaf:OnlineAccount

foaf:holdsAccount property: “The foaf:holdsAccount property relates a foaf:Agent to a

foaf:OnlineAccount for which they are the sole account holder.”

Links a foaf:Person to various sioc:User(s) As many sioc:User(s) as required can be linked to a single

person One people, various identities

A person and their user accounts

FOAF + SIOC = Data Portability

Querying SMC

Find all content created by someone with a given OpenID URL: Browse someone’s social media contributions posted on

various websites using different account names, but for the same person

A single SPARQL query, no need to play with different APIs

SELECT ?item

WHERE { ?person foaf:openid <$openid> ;

foaf:holdsAccount ?user . ?user sioc:creator_of ?item .

Moving data using SIOC

WordPress SIOC import plug-in http://sioc-project.org/wordpress Can read any SIOC RDF data and imports it into WordPress

as a native blog post

Microblogging with SIOC

SMOB - Semantic Microblogging service http://smob.sioc-project.org Publishing and browsing SIOC data

SIOC : More than Web 2.0

SWAN Semantic Web Applications in Neuromedicine http://swan.mindinformatics.org

Recent efforts to align SIOC and SWAN Scientific Discourse representation W3C HCLS Interest Group http://esw.w3.org/topic/HCLSIG/SWANSIOC

Ontologies alignment to provide a complete framework to model activities of scientific communities SIOC to model the online content SWAN to model the discourse

SIOC Adoption

Linked Data

The Linking Open Data initiative Community effort http://linkeddata.org

Lots of information available on the Web Closed world, proprietary data silos

Provide it in RDF and interlink it ! The Web as a giant database From documents to machine-understandable data Use links to discover data by browsing the GGG Open licensing policy

ISWC2008 tutorial on Linked Data

The 4 principles of Linked Data

Tim Berners-Lee, 2006 http://www.w3.org/DesignIssues/LinkedData.html

Use URIs as names for things Use HTTP URIs so that people can look up those

names. When someone looks up a URI, provide useful

information. Include links to other URIs. so that they can

discover more things. Using the rdfs:seeAlso property

URIs and Linked Data

Cool URIs for the Semantic Web http://www.w3.org/TR/2007/WD-cooluris-20071217

A person is not a webpage ! http://apassant.net/alex != http://apassant.net/about

Browsing Linked Data

Client-side Tabulator (FF plug-in)

Server-side Disco, Marbles ...

The LOD cloud

http://richard.cyganiak.de/2007/10/lod/

LOD example: music-related data

http://dbtune.org Music-related RDF platform

LOD-exporters for major music databases and social services MusicBrainz, Jamendo Last.fm, MySpace

Interlinked with references datasets Geonames, DBPedia, riese, FOAF

Advanced querying and browsing features

LOD: Semantic Mash-ups

Bands + locations = dbtune + geonames http://blog.dbtune.org/post/2008/02/06/Playing-with-

Linked-Data-Jamendo-Geonames-Mazzle-and-Songbird

DBpedia

http://dbpedia.org Provide RDF representation of data extracted from

DBpedia More that 2 million concepts (people, places, ...) Internationalization

Interlinking from and to DBpedia Interlinked with other datasets (Geonames, DBLP ...) Can be used in FOAF profiles

– :Alex foaf:topic_interest dbpedia:Semantic_Web

DBpedia URI scheme

Resource URI http://dbpedia.org/resource/Semantic_Web Redirects to its HTML or RDF representation depending on

the user-agent

HTML Document http://dbpedia.org/page/Semantic_Web

RDF Data http://dbpedia.org/data/Semantic_Web

DBPedia example

Querying DBpedia

Hands-on session ! Different kind of queries Going deeper in SPARQL (FILTER, OPTIONAL ...) Will be useful for next assignment

DBpedia provides a SPARQL endpoint http://dbpedia.org/sparql

User interface using SNORQL Pre-defined prefixes, AJAX-rendering ... http://dbpedia.org/snorql/

People born in Galway

Simple triple pattern <http://dbpedia.org/ontology/Person#birthPlace>

:Galway

<http://dbpedia.org/ontology/Person#birthPlace>

People born in Galway

Simple triple pattern <http://dbpedia.org/ontology/Person#birthPlace>

Answer SELECT ?who

WHERE {

?who <http://dbpedia.org/ontology/Person#birthPlace> :Galway .

:Galway

<http://dbpedia.org/ontology/Person#birthPlace>

Japanese name of Galway

Using the FILTER by LANG clause FILTER(lang(?x) = “ja”)

:Galway

rdfs:label

"Galway"@en

rdfs:label

"ゴールウェイ"@ja

Japanese name of Galway

Using the FILTER by LANG clause FILTER(lang(?x) = “ja”)

Answer SELECT ?name

WHERE {

:Galway rdfs:label ?name .

FILTER (lang(?name) = “ja”) .

:Galway

rdfs:label

"Galway"@en

rdfs:label

"ゴールウェイ"@ja

10 first cities in the same county

Combining triples patterns ORDER BY and LIMIT

ORDER BY ASC(?x) LIMIT X

:Galway

?county

dbpedia2:county

foaf:name

"Galway"@e

?city dbpedia2:county

10 first cities in the same county

Combining triples patterns ORDER BY and LIMIT

ORDER BY ASC(?x) LIMIT X

Answer SELECT ?city ?name

WHERE {

:Galway dbpedia2:county ?county .

?city dbpedia2:county ?county ;

rdfs:label ?name .

FILTER(lang(?name) = “en”) .

} ORDER BY ASC (?name) LIMIT 10

:Galway

?county

dbpedia2:county

foaf:name

"Galway"@e

?city dbpedia2:county

Irish cities on the East of Galway

FILTER by type and comparison of coordinates

:Galway

geo:long

rdf:type

-9.041800

geo:long

-6.266111

yago:CitiesInTheRepublicOfIreland

rdf:type

Irish cities on the East of Galway

FILTER by type and comparison of coordinates Answer

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

PREFIX yago: <http://dbpedia.org/class/yago/>

SELECT DISTINCT ?place ?long WHERE {

:Galway geo:long ?glong .

?place rdf:type

yago:CitiesInTheRepublicOfIreland ;

geo:long ?long ;

FILTER (?long > ?glong)

Score of games played in Galway

With OPTIONAL current team of scorers ! OPTIONAL {?s ?p ?o}

?gamedbpedia2:score

dbpedia2:stadium

1-1 ?scorer

dbpedia2:currentclub

:Galway

dbpedia2:goals

?currentclub

dbpedia2:score

dbpedia2:stadium

This one has no score !!

Score of games played in Galway

With OPTIONAL current team of scorers ! OPTIONAL {?s ?p ?o}

ANSWER SELECT ?game ?score ?scorer ?currentclub

WHERE {

?game dbpedia2:stadium :Galway .

dbpedia2:score ?score .

OPTIONAL {

?game dbpedia2:goals ?scorer .

?scorer dbpedia2:currentclub ?club

Conclusion

Social Semantic Web and Linked Data provides lots of RDF data on the Web It’s time to use it ! Web 3.0 ... or Web 0.1 ?

– Berners-Lee, 1989 !

– http://www.w3.org/History/1989/proposal.html

Upcoming challenges

Distributed querying In order to query different endpoints at the same time

Privacy and Trust What should I deliver ? Who should I trust ?

Temporal querying Data evolution

Reasoning Derive new facts from existing ones

References

Some slides based on material from: SAW2008 - Social Network and Data Portability using

Semantic Web Technologies (pdf - slides) SDoW2008 - Combining Social Music and Semantic Web for

music-related recommender systems (pdf - slides)

Additional references Social Data on the Web 2008 workshop

– http://sdow2008.semanticweb.org

Linked Data on the Web 2008 workshop– http://events.linkeddata.org/ldow2008/

W3C SPARQL Tutorial– http://www.w3.org/TR/rdf-sparql-query

+ Tutorials referenced on the previous lecture

the social semantic web and linked data

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