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Microblogging: A Semantic Web and Distributed Approach

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Microblogging: A Semantic Web and Distributed Approach

  1. 1. Microblogging: A Semantic Web and Distributed Approach Alexandre Passant1, Tuukka Hastrup2, Uldis Bojārs2, John Breslin2 1 LaLIC, Université Paris-Sorbonne 2 Digital Enterprise Research Institute, National University of Ireland, Galway Scripting For the Semantic Web (SFSW2008) Tenerife, Spain, 2008-06-02 www.deri.ie  Copyright 2008 Digital Enterprise Research Institute. All rights reserved.
  2. 2. Microblogging overview • Sweet spot between blogging and instant messaging • Short status notification updates – Share your real life with others ! 2
  3. 3. Why and how does it work ? • A ubiquitous network of communication – Various communication channels: Web, phone messages, e-mail – Simple approach for publishing data, following and replying • A fluid network for information exchange in real-time • Services – Online platforms: Twitter, Jaiku, Pownce ... – Plug-ins for existing services: Prologue for WordPress • Microblogging in organisations ? – Corporate microblogging: real-time Q&A – Extends the Enterprise 2.0 vision • Internal Signals (SLATES) 3
  4. 4. Issue #1: Data ownership and portability • A centralised approach – Need to register to (one more!) social platform – “Social Network Fatigue” – Users of different services cannot communicate – Would you use webmail that only allows you to send mail to people using the same provider ? • Users do not own the content they publish – It belongs to a proprietary and closed service – What if it closes ? How do I move my data between services ? – Would you register to a webmail that does not provide POP or SMTP ? • Users do not own their social network – And cannot reuse existing ones: invite, again, again and again ... • Yet, Twitter provides XFN export of people you follow 4
  5. 5. Issue #2: Meta-data • Lack of unified, machine-readable meta-data – Unified queries over a set of services ? • All microblog content posted ten days ago ? – APIs ? • For each service, a new API must be learnt • Extract machine-readable meta-data from Twitter – Merge RSS feeds with XML export available for each update – Map result data with Semantic Web vocabularies • Dublin Core, SIOC... – Use Sindice / SWSE to guess URIs of people • From a user name to a FOAF URI (as in SWAML) – A complex process, latest updates only (RSS-based) 5
  6. 6. Issue #3: Content semantics • Lack of semantics in status updates – Updates dealing with programming languages ? – What happens in my neighbourhood ? • Want to extend meta-data – Locations the post talks about • Hash tags ? Lead to the same issues as tagging – Ambiguity • #paris ? #swig ? – Heterogeneity • #semweb, #websemantique – Lack of organisation • How to relate #rdfa and #semanticweb • Which tags to follow if I’m interested in SW ? 6
  7. 7. Our approach to microblogging • Goal: To provide an open and flexible alternative to current microblogging systems – Distributed, open, user-controlled, reusable, scalable, based on standards • Means: The Semantic Web ! – SIOC and FOAF as the main vocabularies – Semantics for both meta-data and status content – Linked Data principles • Proof of concept: SMOB – Open-source software for distributed microblogging – An ecosystem of distributed publishers and aggregators 7
  8. 8. A common model for meta-data • Modelling users (physical persons) with FOAF – Friend Of A Friend – Ability to reuse one’s personal profile created from an external application (LiveJournal, Flickr exporter ...) – Interlinking various profile URIs on the Web using Linked Data principles • Modelling accounts and data with SIOC – Semantically-Interlinked Online Communities – Linking an existing FOAF profile to an online account, instead of creating yet another disconnected one – Extended with Microblog and MicroblogPost classes • Subclasses of Container and Item – Use other SIOC / DC properties to model the data 8
  9. 9. FOAF + SIOC: Semantics for data portability 9
  10. 10. Post example with the Tabulator • @@@@@@@@@@ 10
  11. 11. Modelling content of status updates • URIs instead of hash tags – Uniform description of resources (DBpedia ...) – Modelled using sioc:topic between the content and the URI • Microblogging enters the Linked Data Web ! – Need to find a user-friendly way to bridge this gap • Prefixed hash tags – #dbp:Effeil_Tower - Simple DBpedia mapping • http://dbpedia.org/resource/Effeil_Tower – #geo:Paris,France - Using geonames.org webservice • Querying the service to retrieve location URI • Can be used in lookup services such as Sindice – New ways to discover content 11
  12. 12. A distributed architecture • Vision: Open, distributed – Follow the spirit of the Web architecture – A network of publishing services and aggregation servers interacting with each other – A microblogging ecosystem – New providers or aggregators can be added at any time, anywhere on the network – Provide standards, methods and open-source tools rather than a closed proprietary approach 12
  13. 13. Architecture overview 13
  14. 14. Data ownership • Publisher stores its content locally, then provide it to aggregators which cache it in a triple store – Data belongs to the user – If an aggregator closes, data is still there – Available in RDF: Mashable, browsable, linkable ... – Can be combined with other Social Media Contributions modeled using SIOC • Retrieve all blog posts and microblogging updates of the last week • Focusing on ideas from “A bill of rights for the Social Web” – http://opensocialweb.org/2007/09/05/bill-of-rights/ – Ownership, Control, Freedom 14
  15. 15. SMOB: A prototype for semantic microblogging • SMOB – http://smob.sioc-project.org – Open-source client and server software to demonstrate principles of our approach – Early stage of development • First prototype in a day and very few lines of PHP – Still a prototype, some challenges to be achieved: • Scalability • SPARQL query complexity on the server side • Authentication • A public SMOB aggregator and anonymous publishing client deployed – 3 weeks, 10 users, 90 posts 15
  16. 16. Publishing content with SMOB • Reusing your FOAF profile – Creating RDF data using the SIOC PHP API • Publishing to various aggregators – Twitter integration, promote SW by using it for your tweets ! 16
  17. 17. Browsing local content • Listing of latest updates, embeds RDFa 17
  18. 18. Storing aggregated content in SMOB server • Aggregators receive pings and cache the RDF documents in real-time • Hash tag interpretation with regular expressions – geonames.org wrapper for #geo: tags – DPpedia links for #dbp: tags • Based on the ARC2 API for storage / queries and Exhibit for the browsing interface – SPARUL “LOAD” pattern to get data – SPARQL to format data to Exhibit JSON – Exhibit for faceted browsing 18
  19. 19. SPARQL query example • Retrieve latest updates from the server (uniquify in PHP) SELECT ?post ?date ?content ?maker ?name ?depiction WHERE { ?post rdf:type sioct:MicroblogPost ; foaf:maker ?maker ; sioc:content ?content ; dct:created ?date . ?maker foaf:name ?name . { ?maker foaf:img ?depiction } union { ?maker foaf:depiction ?depiction } } ORDER BY DESC(?date) LIMIT 20 19
  20. 20. Faceted browsing 20
  21. 21. Faceted browsing with geolocation 21
  22. 22. Security, privacy, authentication • We currently limit access to publishing, aggregation and content viewing by HTTP authentication and API keys – IP-based authentication using .htaccess – Global API key for a microblogging aggregator • All updates are public on the client side • TODO – Authentication schemes (OAuth, OpenID) – Private updates and private communities 22
  23. 23. Future works • More meta-data – Process hash tags before publishing RDF • Linked Data from the client-side • Tags / URIs relationships with MOAT – @replies, linked to FOAF URIs • Other issues – Scalability, authentication, timezones • Intelligent agregators – Browse the SIOC-o-sphere to find relevant updates – Based on their content: • A music aggregator, retrieving only data linking to music bands URIs • Deployment within organisations – Corporate Microblogging in SIOC-based companies 23
  24. 24. Thank you ! • Contacts – http://smob.sioc-project.org – #smob IRC channel on Freenode – sioc-dev on google-groups • SDoW2008 – Social Data on the Web workshop @ ISWC2008 24

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