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Seminar at C4DM - Queen Mary University
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Social music meets the Semantic WebQueen Mary University - Center for Digital Music
16th July 2008
http://flickr.com/photos/8049973@N03/2656140464/ by wolf.tone
Alexandre Passant - apassant.netLaLIC, Université Paris-Sorbonne
Agenda
• Web 2.0, Social Music and the Semantic Web
• Identity and social-networking with FOAF
• Modeling social data with SIOC• Semantic tagging with MOAT• Semantic Web based
recommendations
Web 2.0, Social Music, the Semantic Web
http://flickr.com/photos/wilbertbaan/244105100/ by wilbertbaan
Web 2.0
• Web 2.0 (O’Reilly 2005)• A read/write Web
• From consumers to producers
• Anyone can produce and share data
• Low-technical barriers
• Lots of various services and practices• Blogs, wikis, social networking, tagging ...
• Flickr, Twitter, Slideshare ...
Social Music• Term coined from last.fm• In this talk:
• Social networks from music-related services
• Interlinking music-related data
• Music-related weblogging and tagging
The Semantic Web• An extension of the current Web
(Berners-Lee et. al, 2001)• A machine-understandable Web
• Concepts and relationships rather than documents and hyperlinks• An abstraction layer of interlinked data
• Advanced features• Inference, trust ...
• http://www.w3.org/2001/sw/SW-FAQ
Technical aspects• URIs as identifiers
• Anything can be identified on the Web• http://apassant.net/alex
• RDF to model relationships and properties between concepts• Using triples to define statements• :TheClash rdf:type mo:MusicGroup
• Ontologies to define data semantics• RDFS and OWL
A machine-readable Web
Hyperlink
Web:Documents and
hyperlinks
A machine-readable Web
Hyperlink
Listens to Alexandre Passant Franz Ferdinand
Web:Documents and
hyperlinks
Interpretation
A machine-readable Web
Hyperlink
Listens to Alexandre Passant Franz Ferdinand
<http://dbtune.org/last-fm/terraces>
foaf:Person
<http://zitgist.com/music/artist/aa7a2827-
f74b-473c-bd79-03d065835cf7>
rdf:type
ex:listensTo
mo:MusicArtist
rdf:type
Web:Documents and
hyperlinks
Semantic Web:Data, models
and relationships
Interpretation
Web 2.0
Semantic Web
Limits of Web 2.0 services• Data models
• Each service uses its own model / API
• Need to build specific services
• Documents, hyperlinks rather than concepts and relationships
• Closed worlds• How to share data and connect people
between websites ?
• Social Network Fatigue (Fitzpatrick, 2007)
• The Semantic Web can help !
Web 2.0 + Semantic Web• A web built on social and machine-
understandable data• The Semantic Web to provide a stronger
data model for Web 2.0 services
• Web 2.0 and “wisdom of the crowds” to provide interlinked and structured data
• Languages (FOAF ...), tools (semantic wikis ...), services (revyu.com ...)
• Journal of Web Semantics• Special issue on Web 2.0
“I think we could...have both Semantic Web technology supporting online communities,
but at the same time also online communities can also support Semantic Web data by being the sources of people voluntarily
connecting things together.”
Tim Berners-Lee, ISWC2005 Podcast
Identity and social networking with FOAF
http://flickr.com/photos/poagao/2305789735/ by Poagao
Friend Of A Friend• FOAF : Friend Of A Friend (Brickley
and Miller, 2000)• http://foaf-project.org
• An ontology to describe people, attributes, interests ...
• Social networking with the foaf:knows property, extended with the RELATIONSHIP vocabulary• :me foaf:knows :yves
• :me rel:collaboratesWith :yves
A common model
A common model
FOAF data examples
Querying FOAF data
• FOAF data is RDF data, existing RDF tools and APIs can be used
• A single SPARQL query, wherever the data comes from
• SELECT ?nameWHERE { <$uri> foaf:knows [ foaf:name ?name ]}
Unifiying identity• One exporter = One URI
• lastfm:bob, myspace:bobby, facebook:bob77 ...
• A need to unify one’s identity across services by defining equivalent URIs• Explicit: owl:sameAs
• Implicit: foaf:email, foaf:openid
• Both use reasoning principles
• Interlinking distributed social networks
Interlinked networks
http://apassant.net/blog/2008/01/12/one-foaf-fits-all/
Merging networks• A complete decentralized social graph• Open, distributed, build on standards
(Kinsella, 2007)
Merging networks• A complete decentralized social graph• Open, distributed, build on standards• From various services
(Kinsella, 2007)
Modeling social data with SIOC
http://flickr.com/photos/ejpphoto/2314610838/ by EJP Photo
Modeling Web 2.0 content• SIOC: Semantically-Interlinked Online
Communities (Breslin et al., 2005)• http://sioc-project.org
• An ontology to describe activities of online communities and their Social Media Contributions (SMC)• Common semantics for SMC modeling
• Reusing existing ontologies (FOAF, DC ...)
• W3C Member submission, June 2007• http://www.w3.org/Submission/2007/02
The SIOC Model
http:://rdfs.org/sioc/spec
SIOC data example
SIOC applications• More than 40 applications
• Mainly open-source
• http://rdfs.org/sioc/applications/
• Creating SIOC data• APIs (PHP, Perl ...)
• Exporters for major platforms (Drupal, Wordpress ...) and services (Mailing-lists, IRC ...)
• Consuming SIOC data• RDF tools, SIOC browsers, Agregators
SIOC explorer
http://activerdf.org/sioc
People and accounts
http://sioc-project.org/node/158
People, accounts and SMC
http://www.johnbreslin.com/blog/2008/01/04/dataportabilityorg-web-standards-sioc-and-foaf/
Querying SIOC data
• Retrieving last blog posts and pictures of a given user
• Use FOAF / SIOC relationships to provide a single query for your complete SMC from distributed services
• SELECT ?dataWHERE { <$uri> foaf:holdsAccount ?acc . ?data sioc:has_creator ?acc .}
SIOC Types• SMC are not text-only: pictures, videos,
music, events ...
• A need for more advanced semantics
• SIOC Types module
• http://rdfs.org/sioc/types
• Provides subclasses of Item and Container, aligned with existing ontologies
• AudioChannel and VideoChannel
• dcmi:Sound and dcmi:MovingImage
Modeling playlists
• Combining SIOC and DC to model an online playlist and related songs
• :myRadio a sioct:AudioChannel ;
sioc:contains :song1 ;
sioc:has_creator :me ;
dc:title “Alex’s last.fm playlist” .
:song1 a dcmi:Sound
dc:title “Monkey Man” ;
mo:performer dbpedia:The_Specials .
Linking Open Data
http://www.flickr.com/photos/28509009@N03/2668650475/ by marcreis
The LOD Initiative• Linking Open Data
• http://linkeddata.org
• Lots of information available on the Web• Closed world, proprietary data silos
• Provide it in RDF and interlink it !• From documents to machine-understandable data
• Use links to discover data by browsing the GGG
• Open licensing policy
• WWW2008 talk on Linked Data
The LOD cloud
http://richard.cyganiak.de/2007/10/lod/
Reference datasets• DBpedia (Auer et. al, 2007)
• Wikipedia infoboxes translated into RDF
• Any Wikipedia concept gets a URI:
• http://dbpedia.org/resource/The_Specials
• Geonames• RDF data about more than 6M
geographical entities (countries, cities ...)
• riese (Halb et al., 2008)• RDF description of the Eurostat dataset
Music-related open data• http://dbtune.org (Raimond, 2008)
• 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
Browsing interlinked data
http://blog.dbtune.org/post/2008/02/06/Playing-with-Linked-Data-Jamendo-Geonames-Mazzle-and-Songbird
Semantic tagging with MOAT
http://www.flickr.com/photos/loop_oh/2368779403/ by loop_oh
Tagging• A popular practice on Web 2.0
services to let user index content• Flickr, last.fm, YouTube ...
• Folksonomies• Open and user-driven indexing scheme
• Anyone can use his own terms, no need to learn a classification vocabulary
• Problems when retrieving data• Ambiguity, heterogeneity, lack of
relationship between tags
Tags (as words)
Tags (as words)
Tags (as words)
Tags (as words)
=
Tags (as words)
= =
URIs
http://dbpedia.org/resource/Apple
URIs
http://dbpedia.org/resource/Apple_Inc.
http://dbpedia.org/resource/Apple
URIs
http://dbpedia.org/resource/Apple_Inc.
http://dbpedia.org/resource/Apple
http://dbpedia.org/resource/Apple_Records
URIs
!=http://dbpedia.org/resource/Apple_Inc.
http://dbpedia.org/resource/Apple
http://dbpedia.org/resource/Apple_Records
URIs
!=
!=http://dbpedia.org/resource/Apple_Inc.
http://dbpedia.org/resource/Apple
http://dbpedia.org/resource/Apple_Records
Tagging with URIs ?
• Indexing data with Semantic Web concepts defined by URIs• Solves ambiguity / heterogeneity problems
thanks to understandable identifiers
• Interlinking content thanks to Linked Data
• Challenges • How to find URIs related to a given tag
and define new ones ?
• How to let people easily bridge this gap between tagging and semantic indexing ?
MOAT• Meaning Of A Tag (Passant & al, 2008)
• http://moat-project.org
• A model to represent the meaning of tags• “apple” can refer to various things, but when
I tag this blog post with it, I mean the record company, not the fruit
• A collaborative and open-source framework• A tag server to define and share meanings
• Architecture of participation principles
The MOAT modelmoat:Tag
tags:RestrictedTagging
tags:associatedTag
Resource
tags:taggedResource
Resource URI
moat:tagMeaning
Local meaningGlobal meanings
moat:Meaning
moat:Meaning
moat:hasMeaning
moat:meaningURI
foaf:Agent
foaf:Agent
foaf:makertags:taggedBy
The MOAT framework
User creates content and tag it Client queries the MOAT server
Server returns the setfor global meaning URIs
User chooses local meaning URI
User saves the content
<http://sws.geonames.org/2988507/>
<http://sws.geonames.org/4402452/>
<http://dbpedia.org/resource/Paris_Hilton>
http://example.org/post/1
http://sws.geonames.org/2988507/
http://example.org/tagging/1
Content entersthe Semantic Web
moat:tagMeaning
http://example.org/alex
http://tags.moat-project.org/tag/paris
tags:associatedTag
tags:taggedBy
tags:taggedResource
Semantic Web based recommendations
http://www.flickr.com/photos/yumlog2/20896759/ by yuki*
Recommendations• Common practices
• Bitrate, musical similarity, rythm ...
• Suggest music, content and events thanks to the Semantic Web• Social-networking
• LOD relationships
• SMC and tagged content
• Related work: FOAF-ing the Music (Celma, 2006)
Social Networking
• You may like what your friends are listening to ...
:alex :yvesfoaf:knows
foaf:topic_interest
dbpedia:Ramones
Social Networking
• ... and also the friends of your friends ...
:alex :yvesfoaf:knows :tomfoaf:knows
foaf:topic_interest foaf:topic_interest
dbpedia:Ramones dbpedia:Rancid
Social Networking
• ... from any service
:alex :yvesfoaf:knows :tomfoaf:knows
foaf:topic_interest foaf:topic_interest
dbpedia:Ramones dbpedia:Rancid
Using LOD
• You like a band, what about using DBpedia to see if you may like ...
:alex dbpedia:Beastie_Boysfoaf:topic_interest
Using LOD
• Bands that share concerts with them ?
:alex dbpedia:Beastie_Boysfoaf:topic_interest
p:associatedActs
dbpedia:Bad_Brains
Using LOD
• Their solo members ?
:alex dbpedia:Beastie_Boysfoaf:topic_interest
p:currentMembers
dbpedia:Adam_Yauch
p:associatedActs
dbpedia:Bad_Brains
Using LOD
• Bands from the same music genre ?
:alex dbpedia:Beastie_Boysfoaf:topic_interest
p:currentMembers
dbpedia:Adam_Yauch
dbpedia:Black_Flag_(band)
dbpedia:Hardcore_Punk
p:genre p:genrep:associatedActs
dbpedia:Bad_Brains
Using LOD
• Or even ... somehow related artists ?
:alex dbpedia:Beastie_Boysfoaf:topic_interest
p:currentMembers
dbpedia:Adam_Yauch dbpedia:B._B._King
dbpedia:Category:American_vegatarians
skos:subject skos:subject
dbpedia:Black_Flag_(band)
dbpedia:Hardcore_Punk
p:genre p:genrep:associatedActs
dbpedia:Bad_Brains
SMC and tagged content
• Tag blog posts using SIOC and MOAT ...
:alex
:blogPost1
sioc:creator_of
sioc:topic
dbpedia:The_Clash
sioct:BlogPost
rdf:type
SMC and tagged content
• ... while people tag pictures ...
:alex
:blogPost1
sioc:creator_of
:bob
:picture1
sioc:creator_of
sioc:topic
dbpedia:The_Clash dbpedia:Joe_Strummer
sioc:topic
sioct:BlogPost
rdf:type
exif:IFD rdf:type
SMC and tagged content
• ... find related content ...
:alex
:blogPost1
sioc:creator_of
:bob
:picture1
sioc:creator_of
sioc:topic
dbpedia:The_Clash dbpedia:Joe_Strummer
sioc:topic
p:pastMembers
sioct:BlogPost
rdf:type
exif:IFD rdf:type
SMC and tagged content
• ... once again, everything is distributed
:alex
:blogPost1
sioc:creator_of
:bob
:picture1
sioc:creator_of
sioc:topic
dbpedia:The_Clash dbpedia:Joe_Strummer
sioc:topic
p:pastMembers
sioct:BlogPost
rdf:type
exif:IFD rdf:type
Using the whole data
• Bands that a friend of your friend blogged about, in which the drummer played in the Ska band of the 80’s and that will play in your town next week for less thank £10
• The data is there, on various datasets, we (just) need to write the query ...
Thanks you ! Any questions ?slides @ apassant.net
http://flickr.com/photos/8049973@N03/2656140464/ by wolf.tone
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