The Social Semantic Web and Linked Data

The Social Semantic Web and Linked Data - Presentation Transcript

Digital Enterprise Research Institute www.deri.ie The Social Semantic Web and Linked Data Alexandre Passant <alexandre.passant@deri.org> Digital Enterprise Research Institute, National University of Ireland, Galway DM110 Emerging Web Media 10th November 2008  Copyright 2008 Digital Enterprise Research Institute. All rights reserved. Chapter

Agenda Digital Enterprise Research Institute www.deri.ie  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 ... Digital Enterprise Research Institute www.deri.ie  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 ... Digital Enterprise Research Institute www.deri.ie * Source: Smashcut Media, www.smashcut-media.com

Even more services… Digital Enterprise Research Institute www.deri.ie

It takes a lot of time… Digital Enterprise Research Institute www.deri.ie

Filling out profiles, re-adding your friends… Digital Enterprise Research Institute www.deri.ie

Uploading content to “stovepipes”! Digital Enterprise Research Institute www.deri.ie

Social media sites are like data silos Digital Enterprise Research Institute www.deri.ie * Source: Pidgin Technologies, www.pidgintech.com

Many isolated communities of users and their data Digital Enterprise Research Institute www.deri.ie * Source: Pidgin Technologies, www.pidgintech.com

Need ways to connect these islands Digital Enterprise Research Institute www.deri.ie * Source: Pidgin Technologies, www.pidgintech.com

Allowing users to easily move from one to another Digital Enterprise Research Institute www.deri.ie * Source: Pidgin Technologies, www.pidgintech.com

Enabling users to easily bring their data with them Digital Enterprise Research Institute www.deri.ie * Source: Pidgin Technologies, www.pidgintech.com

Solving the issues Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

Introducing FOAF and SIOC Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie Source: Sheila Kinsella, Applications of Social Network Analysis 2007

Integrating social networks w/ FOAF Digital Enterprise Research Institute www.deri.ie Common formats, Source: Sheila Kinsella, Applications of Social Network Analysis 2007 unique URIs

FOAF from existing data Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

Unified queries Digital Enterprise Research Institute www.deri.ie  Using SPARQL  No matter where the data comes from, as soon as it is exported via FOAF in RDF Alice  SELECT ?f1 ?f2 foaf:name WHERE { :Alice ?f1 foaf:knows ?f2 . foaf:knows } :Bob  {Alice, Bob} :Bill foaf:knows  {Bob, Alex}  {Alex, Bob} foaf:knows :Alex

Distributed identity management Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

Browsing FOAF data Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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/

Digital Enterprise Research Institute www.deri.ie

The SIOC food chain Digital Enterprise Research Institute www.deri.ie

The SIOC Ontology Digital Enterprise Research Institute www.deri.ie  Namespace - http://rdfs.org/sioc/ns  Five top-level classes: User / Role / Space / Container / Item  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 Digital Enterprise Research Institute www.deri.ie

Sample export of SIOC data from vBulletin

Connecting people and accounts Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

FOAF + SIOC = Data Portability Digital Enterprise Research Institute www.deri.ie

Querying SMC Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  SMOB - Semantic Microblogging service  http://smob.sioc-project.org  Publishing and browsing SIOC data

SIOC : More than Web 2.0 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

Linked Data Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  Client-side  Tabulator (FF plug-in)  Server-side  Disco, Marbles ...

The LOD cloud Digital Enterprise Research Institute www.deri.ie http://richard.cyganiak.de/2007/10/lod/ http://richard.cyganiak.de/2007/10/lod/

LOD example: music-related data Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  Bands + locations = dbtune + geonames  http://blog.dbtune.org/post/2008/02/06/Playing-with- Linked-Data-Jamendo-Geonames-Mazzle-and-Songbird

DBpedia Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie

Querying DBpedia Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  Simple triple pattern  <http://dbpedia.org/ontology/Person#birthPlace> ?who <http://dbpedia.org/ontology/Person#birthPlace> :Galway

People born in Galway Digital Enterprise Research Institute www.deri.ie  Simple triple pattern  <http://dbpedia.org/ontology/Person#birthPlace> ?who <http://dbpedia.org/ontology/Person#birthPlace>  Answer  SELECT ?who :Galway WHERE { ?who <http://dbpedia.org/ontology/ Person#birthPlace> :Galway . }

Japanese name of Galway Digital Enterprise Research Institute www.deri.ie  Using the FILTER by LANG clause  FILTER(lang(?x) = “ja”) \"Galway\"@en rdfs:label :Galway rdfs:label \" \"@ja

Japanese name of Galway Digital Enterprise Research Institute www.deri.ie  Using the FILTER by LANG clause  FILTER(lang(?x) = “ja”) \"Galway\"@en rdfs:label :Galway  Answer rdfs:label \" \"@ja  SELECT ?name WHERE { :Galway rdfs:label ?name . FILTER (lang(?name) = “ja”) . }

10 first cities in the same county Digital Enterprise Research Institute www.deri.ie  Combining triples patterns \"Galway\"@e foaf:name  ORDER BY and LIMIT :Galway  ORDER BY ASC(?x) dbpedia2:county  LIMIT X ?city dbpedia2:county ?county

10 first cities in the same county Digital Enterprise Research Institute www.deri.ie  Combining triples patterns \"Galway\"@e foaf:name  ORDER BY and LIMIT :Galway  ORDER BY ASC(?x) dbpedia2:county  LIMIT X ?city dbpedia2:county ?county  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

Irish cities on the East of Galway Digital Enterprise Research Institute www.deri.ie  FILTER by type and comparison of coordinates ?city -9.041800 geo:long geo:long :Galway rdf:type rdf:type -6.266111 yago:CitiesInTheRepublicOfIreland

Irish cities on the East of Galway Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  With OPTIONAL current team of scorers !  OPTIONAL {?s ?p ?o} 1-1 dbpedia2:score ?game dbpedia2:goals ?scorer dbpedia2:stadium dbpedia2:currentclub :Galway 2-1 dbpedia2:stadium ?currentclub dbpedia2:score dbpedia2:stadium ?game ?game This one has no score !!

Score of games played in Galway Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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 Digital Enterprise Research Institute www.deri.ie  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