The Social Semantic Web: An Introduction

The Social Semantic Web: An Introduction Alexandre Passant, John Breslin {firstname.lastname@deri.org} DERI Tutorial / NUI Galway / 2 nd April 2009

What we’re going to talk about today…
Collaborating via the Social Web
Social networking websites so far
Issues with social websites
Leveraging semantics on the Social Web:
FOAF, SIOC, semantic tagging
The social semantic food chain: Producers, Collectors, Consumers
Applications and demos
Leveraging semantics in Enterprise 2.0
Semantics for Enterprise 2.0
Semantic wikis
Conclusion and references

Social media sites are like data silos * Source: Pidgin Technologies, www.pidgintech.com

Many isolated communities of users and their data * Source: Pidgin Technologies, www.pidgintech.com

Need ways to connect these islands * Source: Pidgin Technologies, www.pidgintech.com

Allowing users to easily move from one to another * Source: Pidgin Technologies, www.pidgintech.com

Enabling users to easily bring their data with them * Source: Pidgin Technologies, www.pidgintech.com

1. Collaborating via the Social Web

A move from the Web to a “social web”
The New Yorker, 1993
“ On the Internet, nobody knows you’re a dog.”
The New Yorker, 2005
“ I had my own blog for a while, but I decided to go back to just pointless, incessant barking.”

What is social media?
http://en.wikipedia.org/wiki/Social_media
“ Social media uses the ‘wisdom of crowds’ to connect information in a collaborative manner.”
“ Social media can take many different forms, including message boards, weblogs, wikis, podcasts, pictures and video.”
Popular examples of social media sites:
Wikipedia, MySpace / Facebook, Twitter, YouTube, SecondLife, Upcoming, Digg / Reddit / StumbleUpon, Flickr / Zooomr, del.icio.us, World of Warcraft, Amazon
Related terms:
Web 2.0, Social Web , social software, social networks, social news, social bookmarking, user-generated content

What is Web 2.0?
http://en.wikipedia.org/wiki/Web_2.0
“ Web 2.0 refers to a perceived second generation of web-based communities and hosted services - such as social-networking sites, wikis and folksonomies - which aim to facilitate collaboration and sharing between users.”
The term Web 2.0 was made popular by Tim O’Reilly:
http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html

Features / principles of Web 2.0 (O’Reilly)
The Web as platform
Harnessing collective intelligence
Data is the next “Intel Inside”
End of the software release cycle
Lightweight programming models
Software above the level of a single device
Rich user experiences
The long tail

Web 2.0 and social media in simple terms
Users
Content
Tags
Comments
Users post content
Users share content
Users annotate content with tags
Users browse content via tags
Users discuss content via comments
Users connect via posted content
Users connect directly to users

Content can be…
Books Amazon
Discussion postings Blogs
Bookmarks del.icio.us
Photos Flickr
Music Last.fm
Movies Netflix
Events Upcoming.org
Places Dopplr
Products Microsoft Aura
Articles Wikipedia

Blogging: a phenomenon for a new generation?
Cincinnati Enquirer, October 2004

Overview of blogs
Weblog , web log or simply a blog is a web journal
“ A web application which contains periodic time-stamped posts on a common (usually open-access) webpage”
Individual diaries -> arms of political campaigns, media programs and corporations (e.g. the Google Blog)
Citizen journalism…
Posts are often shown in reverse chronological order
Comments can be made by the public on some blogs
Latest headlines, with hyperlinks and summaries, are syndicated using RSS or Atom formats (e.g. for reading favourite blogs with a feed reader)

The state of the blogosphere from Technorati

Definition of wikis
A wiki is a type of website that allow users to easily add and edit content and is especially suited for collaborative writing
The name is based on the Hawaiian term wiki-wiki, meaning “quick”, “fast”, or “ to hasten ”
It amasses to a group of web pages that allows users to quickly add content and also allows others to edit the content:
It relies on cooperation, checks and balances of its members, and a belief in sharing of ideas

Some uses of wikis
Wikis are being used for:
online encyclopaedias
free dictionaries
book repositories
software development
project proposals
writing research papers
event organisation

The Wikipedia: from Irish to Esperanto

Flickr, share your photos

SlideShare for presentations

The social bookmarking service del.icio.us

All Consuming, what have you read today?

CiteULike, get publication references from peers

Upcoming event listings and meetups

Dopplr for managing travel, tracking friends abroad

You can even share your favourite walks…

… and find others with like musical interests

2. Social networking websites so far

We all live in a social network…
… of friends, family, workmates, fellow students, acquaintances, etc.

Friend of a friend, or “dúirt bean liom go ndúirt bean leí”
Theory that anybody is connected to everybody else (on average) by no more than six degrees of separation
Everyone’s connected…

Milgram’s six degrees of separation theory
Sociologist Milgram conducted this experiment:
Random people from Nebraska were to send a letter (via intermediaries) to a stock broker in Boston
Could only send to someone with whom they were on a first-name basis
Among the letters that found the target, the average number of links was six
Stanley Milgram (1933-1984)

And now a major motion picture, kind of…
Six Degrees of Separation (1993)
“ I read somewhere that everybody on this planet is separated by only six other people. Six degrees of separation between us and everyone else on this planet. The President of the United States, a gondolier in Venice, just fill in the names... It’s not just big names — it’s anyone. A native in a rain forest, a Tiero del Fuegan, an Eskimo. I am bound — you are bound — to everyone on this planet by a trail of six people.”
Play from 1990 by John Guare

The Erdős number
Number of links required to connect scholars to Erdős via co-authorship of papers
Erdős wrote 1500+ papers with 507 co-authors
Jerry Grossman’s site allows mathematicians to compute their Erdős numbers:
http://www.oakland.edu/enp/
Connecting path lengths, among mathematicians only:
The average is 4.65
The maximum is 13
Paul Erdős (1913-1996)

Trying to make friends Valdis Marc Met Marc and I already had friends in common! I later found out my cousin Ailish also knows Andrew. The “small world” phenomenon… Latvia Uldis DERI John Dublin Clare Bros John C Andrew

“ It’s a small world after all!”, by Kentaro Toyama Kentaro Bash Karishma Sharad Maithreyi Anandan Venkie Soumya Prof. McDermott * Source: http://research.microsoft.com/toyama/talks/ Ranjeet Prof. Sastry PM Manmohan Singh Prof. Balki Pres. Kalam Prof. Jhunjhunwala Dr. Montek Singh Ahluwalia Ravi Dr. Isher Judge Ahluwalia Pawan Aishwarya Ravi’s Father Amitabh Bachchan Prof. Kannan Prof. Prahalad Nandana Sen Prof. Amartya Sen Prof. Veni

The Kevin Bacon game
Boxed version of the game
Invented by three Albright College students in 1994:
Craig Fass, Brian Turtle, Mike Ginelly
Goal is to connect any actor to Kevin Bacon, by linking actors who have acted in the same movie
The “Oracle of Bacon” website uses IMDB to find the shortest link between any two actors:
http://oracleofbacon.org/

The Kevin Bacon game (2)
Total number of actors in database as of today:
1036399
Average path length to Kevin:
2.945
Actor closest to “center”:
Rod Steiger (2.68)
Rank of Kevin, in terms of closeness to center:
1049th
Most actors are within three links of each other!

What are social networking services (SNSs)?
From the beginning, the Internet was a medium for connecting not only machines but people
Idea behind SNSs is to make the aforementioned real-world relationships explicitly defined online
2002:
Friendster
2003:
MySpace, LinkedIn, hi5
2004:
orkut, Facebook
2005:
Bebo

The popularity of SNSs
The 10 most popular domains ~= 40% percent of all page views on the Web (Compete, November 2006)
Nearly half of those views were from the social networking services MySpace and Facebook – wow!
And that’s just in the top 10…
Alexa rankings

SNSs attracting lots of monetary / media attention
Friendster – $13M VC
Tribe – $6.3M VC
LinkedIn – $4.7M VC
Bebo – $15M VC, sold to AOL for $850M
MySpace – Sold for $580M
Friends Reunited – Sold for £120M
Facebook – $1B Y! offer, 1.6% sold to MS for $250M

Motivation for social network services
Allows a user to create and maintain an online network of close friends or business associates for social and professional reasons :
Friendships and relationships
Offline meetings
Curiosity about others
Business opportunities
Job hunting
…
For social good:
Kevin Bacon – sixdegrees.org
Ammado - ammado.com
Sun – openeco.org

Big social network services (in terms of accounts)
myspace.com 250,000,000
facebook.com 175,000,000
spaces.live.com 120,000,000
habbo.com 117,000,000
friendster.com 90,000,000
hi5.com 80,000,000
tagged.com 70,000,000
orkut.com 67,000,000
flixster.com 63,000,000
reunion.com 51,000,000
classmates.com 50,000,000
netlog.com 42,000,000
http://en.wikipedia.org/wiki/List_of_social_networking_websites

Features of social network services
Network of friends (inner circle)
Person surfing
Private messaging
Discussion forums
Events management
Blogging and commenting
Media uploading

Facebook, #5 in the world

The success of (and hype around) Facebook
Some have theorised that Facebook is worth $15-$20B!
http://scobleizer.com/2008/05/19/why-microsoft-will-buy-facebook-and-keep-it-closed/
4,000 applications were created for Facebook’s developer interface after four months, 70,000 developers signed up:
Active user count jumped by 70% in the four months after this contributable application layer was added
In mid-2008, the numbers had increased to 33,000 applications and 400,000 developers
50% of Facebook users are non-students:
People over 24 are its fastest-growing demographic

orkut, Google’s SNS

Get LinkedIn to business contacts, 15 million users

OpenEco, a SNS for managing GHG emissions

Elgg, social networking software for education

The Twitter phenomenon
Microblogging:
Between blogging and IM
Short messages
Multiple devices
Twitter:
140 characters maximum
+1 billion tweets
+ 1382 % in a year !

Other niche SNSs
Age:
Multiply (seniors and settled); Boomj (baby boomers); Rezoom
Country of origin:
Silicon India
Gender:
CaféMom; MothersClick; Sister Woman (female friends)
Occupation:
ModelsHotel; FanLib (fiction writers); AdGabber; TheFeng.org (financial services executives); MilitarySpot (military families); Sermo (doctors and physicians)
Business and careers:
ConnectBuzz; Doostang; Execunet; Netshare; Ryze; Viadeo; Xing
Interests:
TradeKing (investors); StreetCred (hip hop); IndiePublic (art and design); PeerTrainer (health and wellbeing)
* Source: Paul Gibler, Wisconsin Technology Network

3. Issues with social websites

Problems with social websites
Fundamental problems block their potential to access the full range of available content and networked people online
There is a need to build semantic social networking into the fabric of the next-generation Internet itself:
Interconnecting both content and people in a meaningful way

First issue
Need interesting objects to draw you back to keep on using social websites
* Source: Jyri Engestrom, “Object-Centered Sociality”, Reboot 7

Many social websites are boring… * Source: Jyri Engestrom, “Object-Centered Sociality”, Reboot 7

Object-centred sociality can provide meaning
Users connected via a common object, e.g., their job, university, hobbies, a date…
“ Another tradition of theorizing offers an explanation of why Russell linked out, and why so many YASNS ultimately fail.”
“ According to this theory, people don’t just connect to each other. They connect through a shared object.”
* Source: Jyri Engestrom, “Why Some Social Networks Work…”

Object-centred sociality can provide meaning (2)
“ When a service fails to offer the users a way to create new objects of sociality, they turn the connecting itself into an object [LinkedIn].”
“ Good services allow people to create social objects that add value.”
Flickr = photos
del.icio.us = bookmarks
Blogs = discussion posts
* Source: Jyri Engestrom, “Why Some Social Networks Work…”

… that connect us to other people
Discussions
Bookmarks
Annotations
Profiles
Microblogs
Multimedia
…
These are the social objects…

Second issue
We all have too many separate profiles and sets of contacts on disconnected social websites

So many social websites… * Source: Smashcut Media, www.smashcut-media.com

Even more services…

It takes a lot of time…

Filling out your profiles, re-adding your friends…

Uploading posts and content items to “stovepipes”!

What if I use multiple services and I want to…
Move the stuff I have on one service to another (e.g. move all my blog posts, comments, friends, etc. from WordPress.com to “Acme Blogs”)
Move all my stuff from multiple services to one third-party service
Centralise my stuff on my own service, e.g. my blog
See my stuff on a third-party service providing an aggregate view, like FriendFeed
Share my Flickr pictures with my Twitter followers

(De-)centralised me

Initiatives set up to address this recently
A bill of rights for users of the Social Web:
http://opensocialweb.org/
DataPortability:
http://dataportability.org/
DiSo:
http://code.google.com/p/diso/
OpenSocial (see also Friend Connect):
http://opensocial.org/
Facebook Connect:
http:// developers.facebook.com/connect.php
Portable Contacts:
http://portablecontacts.net/

Social network portability
Need distributed social networks and reusable profiles
Users may have many identities and sets of friends on different social networks, where each identity was created from scratch
Allow user to import existing profile and contacts, using a single global identity with different views (e.g., via FOAF, hCard, OpenID, etc.)
See also:
http://bradfitz.com/social-graph-problem/
http://danbri.org/words/2007/09/13/194
http://code.google.com/apis/socialgraph/
http://groups.google.com/group/social-network-portability

Social networking fatigue
How many general or niche SNSs are you willing to register and / or interact with?
People search engine and aggregation sites are now appearing to compensate:
SocialURL – organise your online identities
PeekYou – matching web pages with their owners
Spock – organising information around people
Rapleaf – reputation lookup and email search
Wink – free people search engine
FriendFeed – subscribe to all of your friends’ feeds

Ownership, control, freedom at opensocialweb.org

The DataPortability initiative
http://dataportability.org
Existing technologies
Inventing no new ones

Other initiatives “near” DataPortability
Depends on “political” factors
e.g. Facebook vs Google

Fold a social networking layer into tech stacks
Make social networking a shared component across various desktop and Web applications
Rather than having a fragmented view of one’s network in each application, the social networking stack would let users employ all their person-to-person connections in any application:
See http://tinyurl.com/futuresns

4. Leveraging semantics on the Social Web

Tim Berners-Lee on Semantic Web / Social Web synergies
“ 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 .”
Sir Tim Berners-Lee, podcast interview during ISWC 2005
http://esw.w3.org/topic/IswcPodcast

Semantics can help
By using agreed-upon semantic formats to describe people, content objects and the connections that bind them all together , social media sites can interoperate by appealing to common semantics
Developers are already using semantic technologies to augment the ways in which they create, reuse, and link profiles and content on social media sites (using FOAF, XFN / hCard, SIOC, etc.)
In the other direction, object-centered social networks can serve as rich data sources for semantic applications

The (evolving) Semantic Web layer cake
http://www.w3.org/2007/03/layerCake.png

A need for common semantics
Communities should provide their data in a common, machine-understandable way:
RDF (resource description framework) as a data layer
One single format for all the data
Different transport layers (RDF/XML, N3, etc.) ‏
The base of the Semantic Web
Communities should use common semantics to define this data:
Avoiding the use of proprietary APIs
Since this means that they can talk together, exchange information, using the same modelling layer for their data
Using SIOC for representing content and actions
Using FOAF for representing people and networks

FOAF (Friend-of-a-Friend)
FOAF is an ontology for describing people and the relationships that exist between them
http://foaf-project.org
Can be integrated with any other SW vocabularies
Some services with FOAF exports:
People can also create their own FOAF document and link to it from their homepage
FOAF documents usually contain personal info, links to friends, and other related resources

A distributed social network with FOAF
Can use FOAF to describe social networks across a number of services (more later on integrating networks)
Picture shows data from both boards.ie and John’s hand-coded FOAF file

The (lowercase) semantic web
Microformats:
http://microformats.org/
“ Designed for humans first and machines second, microformats are a set of simple, open data formats built upon existing and widely adopted standards.”
Embedded metadata within (X)HTML web pages
Less powerful than RDF (no extensibility mechanism, no inferencing)

Semantically-Interlinked Online Communities (SIOC)
An effort from DERI to discover how we can create and establish ontologies on the Semantic Web
Goal of the SIOC ontology is to address interoperability issues on the (Social) Web
SIOC has been adopted in a framework of 50 applications or modules deployed on over 400 sites
Various domains: Web 2.0, enterprise information integration, HCLS, e-government
http://sioc-project.org

Motivations for SIOC
Need to understand how to create and establish ontologies on the Web:
Social engineering is required
Model, agree, deploy, re-model
Disconnected sites on the Social Web require ontologies for interoperation:
Lots of social data, inherent semantics (chicken and egg)
Potential for high impact
In parallel, lack of integration between social software and other systems in enterprise intranets

The aims of SIOC
To “semantically-interlink online communities”
To fully describe the content and structure of community sites
To create new connections between online discussion posts and items, forums and containers
To enable the integration of online community information
To browse connected Social Web items in interesting and innovative ways
To overcome the chicken-and-egg problem with the Semantic Web

The steps involved
Develop an ontology of terms for representing rich data from the Social Web
Create a food chain for producing, collecting and consuming SIOC data
As well dissemination via papers about SIOC, provide docs and examples at sioc-project.org
SIOC aims to enrich the Web infrastructure:
During the next upgrade cycle, gigabytes of community data become available!

The SIOC food chain

Dissemination

Quotes about SIOC
“ I […] think the concept is HOT” – Robert Douglass, Drupal Developer
“ It just dawned on me that the burgeoning SIOC-o-sphere (online communities exporting and exposing content via SIOC Ontology) is actually: Blogosphere 2.0” – Kingsley Idehen, Founder and CEO of OpenLink Software
“ SIOC has the potential to become one of the foundational vocabularies that make Semantic Web applications useful” – Ivan Herman, W3C / ERCIM
“ A project that started back in 2000 called Friend-of-a-Friend (FOAF) represents relationships between people, as well as basic contact details. SIOC does this for groups: it extends the FOAF idea to being able to talk about whole groups of people. I am excited about SIOC because you can use that information to determine trust, to let people in.” – Tim Berners-Lee, Creator of the World Wide Web

SIOC metrics
SIOC documents at PTSW:
107759 (SIOC)
96540 (SIOC Types)
42911 hits in Swoogle
Sites producing SIOC data:
373 listed in PTSW pings
SIOC ontology is ranked 4 th and SIOC Types module 5 th in 500 ontologies at PTSW
SIOC developer mailing list:
200 members
900 posts

What is required to represent a community?
Represent the data, not only documents:
From the WWW to a “GGG”, hyperlinks to semantic relationships
A model for all the aspects of a community:
Users accounts, groups and roles:
Reader, reviewer, moderator
Content and types:
A blog, a blog post, a bulletin board, a wiki page, etc.
Actions between users and content:
Uldis creates a post, Alex comments on it, John moderates it
A model for the entire content:
Any data: RSS 1.0 and Atom limited to syndication / latest posts
Any user and relationship: new user, new post, replies, etc.

Representing community data with SIOC
Using SIOC as an ontology to represent the activities of online communities on the Web:
Namespace: http://rdfs.org/sioc/ns
Five top-level classes: User / Role / Space / Container / Item
A “SIOC Types” module for Social Web content
Wikis, Blogs, Image galeries …
Action: A user posts an item in a container
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
The main classes and properties are:
SIOC Specification: http://rdfs.org/sioc/spec

Example of SIOC data
Alex wrote a post on his WordPress blog:
:myblogpost rdf:type sioc:Post ;
dc:title “I’m blogging this” ;
sioc:has_creator :alex ;
sioc:has_container :mywpblog .
:mywpblog rdf:type sioc: Forum .

The same model for any website
John wrote a post on his Drupal-powered blog:
:myblogpost rdf:type sioc:Post ;
dc:title “Another blog post” ;
sioc:has_creator :john ;
sioc:has_container :mydrupal .
:mydrupal rdf:type sioc: Forum .

The same model for rich data using the Types module and related ontologies
Uldis owns a photo gallery on Flickr:
:myitempost rdf:type exif:IFD ;
dc:title “Another posted item”;
sioc:has_creator :john ;
sioc:has_container :myflickrgallery .
:myflickrgallery rdf:type sioct:ImageGallery .
We reuse external vocabularies (e.g. EXIF) to define item types

Interlinking communities
Since all communities can use the same model to define their data, it is easy to link them from a data point of view
Interlinking:
URIs are used to define things and created objects
A post on blog “A” can be semantically linked to a post on blog “B”
Using SPARQL to query data:
Can perform unified queries no matter where the data comes from
No need to learn new APIs from data providers
SPARQL is a W3C Recommendation for querying RDF
“ The SQL of the Semantic Web”

FOAF and social network connections
FOAF allows us to represent the connections between people:
A machine-readable format for social-networking
Using the foaf:knows property:
:John foaf:knows :Alex
Extensions using the RELATIONSHIP vocabulary:
http://vocab.org/relationship/
All rel:* properties are subproperties of foaf:knows
:John rel:worksWith :Uldis
RDFS inferencing allows tools to answer queries using foaf:knows when people use rel:* alternatives

Linking people to user accounts
FOAF is the main vocabulary used to represent people:
http://foaf-project.org
foaf:Person class:
“ The foaf:Person class represents people. Something is a foaf:Person if it is a person.”
foaf:holdsAccount property:
“ The foaf:holdsAccount property relates a foaf:Agent to a foaf:OnlineAccount for which they are the sole account holder.”
Linking people to user accounts:
sioc:User rdfs:subClassOf foaf:onlineAccount
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

Representing users and online accounts
The sioc:User class:
An online user account
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
Various properties:
name, avatar, email
Users create and manage content:
has_creator and has_modifier properties
:blogpost123 sioc:has_creator :john
A user can have roles on a given container:
(Moderator, Forum 1) ← User A
(Contributor, Blog 2) ← User B

A person and their user accounts

Interlinking content with SKOS
skos:isSubjectOf
sioc:topic

Interlinking content items
Can create direct links between instances of sioc:Item:
Link from a blog post to a bulletin board page
sioc:related_to, sioc:links_to, sioc:has_reply
Interlinking using common categories:
Share tags and topics across different content
SKOS: Simple Knowledge Organisation System
http://www.w3.org/2004/02/skos/
A vocabulary to describe controlled vocabularies
Used in the “Tag Ontology”: http://www.holygoat.co.uk/projects/tags/
Interlink using existing URIs as topics
geonames.org , DBpedia, Revyu
MOAT: a process to simplify linking content to such URIs
http://moat-project.org/

Identity management across networks
Social media sites (or RDF exporters) create a new foaf:Person instance when they export their data:
TalkDigger, Revyu, Flickr exporters, etc.
There is a need to unify URIs so as to represent one's unified identity
Linked-data principles are to use owl:sameAs and rdfs:seeAlso:
See http://www4.wiwiss.fu-berlin.de/bizer/pub/LinkedDataTutorial/
owl:sameAs: Used to identify two resources with different URIs as being the same resource
rdfs:seeAlso: “More information about this resource can be found here”, can be used by Semantic Web tools such as Tabulator
Inference using owl:InverseFunctionalProperty:
foaf:mbox, foaf:openid, etc. can be used to identify uniqueness for a foaf:Person
Unifying aspects of a foaf:Person across networks:
All relevant sioc:User accounts may be related to one foaf:Person

Distributed social networking with FOAF
Combining networks from multiple FOAF URIs via owl:sameAs:
Decentralised social networks can represent connections for the same person
A person’s networks can be merged together
Any sub-network in the social graph can be reached from a single entry point, via the person’s URI

Integrating social networks with FOAF Common formats, unique URIs * Source: Sheila Kinsella, Applications of Social Network Analysis 2007

:alex owl:sameAs flickr:33669349@N00 ;
owl:sameAs twitter:terraces
Linking foaf:Person URIs for one person

Applications for browsing the social (semantic) graph
FOAFnaut, FOAF Explorer, etc.
FOAFGear: thanks to common semantics, only 100 lines of code: http://apassant.net/home/2008/01/foafgear/

Aggregation of semantic social networks
Browse / re-use your social graph in personal applications
Merge identities with pre-defined rules
Tools:
Beatnik
Knowee
SPARQLpress
Nepomuk (Social Semantic Desktop)

Using OpenID with FOAF
OpenID provides a decentralised authentication scheme:
One single login / password for various sites
http://openid.net
Can link to your FOAF profile from your OpenID URL, and from the FOAF file to the OpenID URL (foaf:openid) so that services can browse your machine-readable profile when you log in:
<head>
<link rel="meta" type="application/rdf+xml" title="FOAF" href="foaf.rdf" />
</head>

Example of OpenID used with FOAF
Bob creates an account on Networkr, a new social networking website, using OpenID
Networkr retrieves the FOAF URI thanks to an auto-discovery link
From the FOAF file, it identifies if there are any people already subscribed to Networkr who are listed in Bob’s defined relationships:
Bob can add them as “local connections”, share data with them, etc. without having to once again search for / add his friends
Specific rules:
If I know X from Flickr, he / she can see my pictures on Networkr

OpenID, FOAF and WordPress
SparqlPress:
http://wiki.foaf-project.org/SparqlPress
Create and re-use RDF data within WordPress
Exports SIOC, FOAF, SKOS:
Currently under development
FOAF retrieval from OpenID

SIOC d ata p roducers
SIOC a pplications l ist :
http://rdfs.org/sioc/applications/
> 20 a pplications for p roducing SIOC d ata :
F ree and o pen s ource
SIOC e xport t ools for:
Blogs and forums: WordPress, phpBB, Drupal, b2evolution
“ Legacy” applications: m ailing lists, IRC
New media: Twitter, Jaiku , Facebook, Flickr
Enterprise applications: CWE (collaborative work environments)

Overview of WordPress SIOC exporter
Installation:
Download from http://sioc-project.org/wordpress
“ Drop” two files into the WordPress plugins folder
Go to the administrator’s user interface
Plugins -> SIOC Plugin -> “Activate”
SIOC data created for every page:
Data describing all blog posts, comments, users, etc.
SIOC data can be discovered via RDF autodiscovery links:
E.g. http://www.johnbreslin.com/blog/
<link rel="meta" type="application/rdf+xml" title="SIOC" href="http://www.johnbreslin.com/blog/index.php?sioc_type=site" />
Data can be explored or crawled using existing Semantic Web applications

Sample export of SIOC data from WordPress

RDF data from the WordPress SIOC Exporter, displayed in the SIOC RDF Browser

SIOC export APIs
Benefits:
Hides the complexity from application developers
Can be used by people who are not Semantic Web experts
Automatically updated according to changes in the SIOC ontology and best practices documents
Existing SIOC APIs:
Java
Perl
PHP (most used)
RDFa on Rails
See “2.1 SIOC APIs” in http://rdfs.org/sioc/applications/

Overview of vBulletin and phpBB SIOC Exporters
There is a large amount of structured related information contained within message boards, and this can be leveraged in interesting ways by exposing the semantic data for new applications
Exporters have been developed for commercial (vBulletin) and open-source (phpBB) message board systems, bringing these islands together and allowing conversations on topics that are taking place across various sites
vBulletin and phpBB SIOC Exporters are based on the SIOC API for PHP:
http://wiki.sioc-project.org/index.php/PHPExportAPI

Sample export of SIOC data from vBulleti n

Sample export of SIOC data from vBulleti n (2)

boards.ie SIOC data competition

Creating your own exporters
Use SIOC API(s) if possible:
Or create new APIs to contribute back to the community
Creating RDF data is easy:
Use the plugin API provided by the host system
Collect required information from the host (CMS) system
Create in-memory RDF or object model (optional)
Serialise RDF data (using RDF API or print templates)
Seek help from the SIOC developer community:
http://sioc-project.org/ or SIOC-Dev mailing list or #sioc on IRC

Explore more producers of SIOC data
Sioku:
SIOC data from Jaiku microblogging service
http://sioku.sioc-project.org/
SWAML:
Exports mailing list archives in RDF
http://swaml.berlios.de/
OpenLink DataSpaces:
Uses SIOC as a representation format for multiple social spaces
http://virtuoso.openlinksw.com/wiki/main/Main/OdsIndex/
Use the Semantic Radar extension for Firefox for detecting / exploring SIOC data:
http://sioc-project.org/firefox

SIOC exporter for MediaWiki
Available at http://ws.sioc-project.org/mediawiki/
Any MediaWiki website can be translated to SIOC:
Wikipedia, semanticweb.org, etc.
Ideally combined with DBpedia

There is a lot of Social Semantic Web data available:
From services
Via exporters
Hand-crafted
But it is scattered all around the Web:
How do we find, browse, query, reuse it?
These need to be addressed:
To provide novel applications that can leverage the interlinked nature of this data from the Social Web
To show the benefits of RDF and the Semantic Web
Motivation for finding and reusing semantic data

Finding data from the Social SW
PingTheSemanticWeb:
http://pingthesemanticweb.com
A ping service for SW documents
REST or XML/RPC
Accepts, reads different formats:
RDF/XML, N3, Turtle
The “blo.gs” of the Semantic Web
Various ontologies detected by PTSW:
FOAF, DOAP, SIOC, etc.
About 1M documents, 3.7M pings
“ A Scripting Architecture to Discover and Query Decentralized RDF Data”, The 3rd Workshop on Scripting for the Semantic Web (SFSW 2007), Innsbruck, Austria, June 2007

Direct ping to PingTheSemanticWeb:
Blog engine s : WordPress, Drupal, etc.
Services: Revyu, TalkDigger
“ Semantic Radar” extension for Firefox:
http://sioc-project.org/firefox
Easy to setup and use (Firefox extension, auto-update)
Support for RDFa!
Architecture of participation: just browse the Web
Discover Semantic Web documents using RDF autodiscovery links (a popular practice for advertising Atom/RSS and FOAF ):
<head>
<link rel="meta" type="application/rdf+xml" title="FOAF" href="http://example.com/people/~you/foaf.rdf"/>
</head>
Advertising RDF data to PTSW

Semantic Radar in action, sending pings to PTSW Click to view SW data.

PTSW acts as a central access point for RDF data:
Subscribe to the service
Ask for recent updates
Apply namespace restrictions (e.g. export FOAF only)
Get fresh Semantic Web data
Concentrate on your tools, rather than on finding the data
Reusing data from PTSW

Sindice:
Lookup service for Semantic Web documents
doap:store:
DOAP-based projects directory
SWSE, Zitgist, Swoogle:
Semantic Web search engines
Existing services that can make use of PTSW

doap:store

Write your own Social Semantic Web application
Find data:
Subscribe to PTSW
Make a crontab script to regularly fetch new data
Store data:
Plain-text files
RDF stores
Query the data:
SPARQL query language and protocol, a W3C recommendation
“ Trying to use the Semantic Web without SPARQL is like trying to use a relational database without SQL” - Tim Berners-Lee

Storing RDF data
RDF stores:
Storage systems for triples
Better performance that distributed queries
Some support inference engines (OWL, RDFS)
Many provide an open SPARQL endpoint to let people use data
Various implementations:
YARS (Java)
ARC2 (PHP)
3Store (C)
Virtuoso, etc.

Querying RDF data
SPARQL language:
A language to query a set of triples
REST-protocol between clients and endpoint
Results in standard formats (XML or JSON)
http://www.w3.org/TR/rdf-sparql-query/
SPARQL endpoint:
Remotely accessible data
Data openness
Easy to use , e.g. ARC2 requires just three lines of code:
include_once('path/to/arc/ARC2.php');
$ep = ARC2::getStoreEndpoint(array(...));
$ep->go();

Semantic Web Search Engine (SWSE)
A large-scale Semantic Web search engine developed and run by DERI Galway :
http://swse.deri.org/
Andreas Harth, Jürgen Umbrich, Aidan Hogan, Stefan Decker , “ YARS2: A Federated Repository for Querying Graph Structured Data from the Web”, The 6th International Semantic Web Conference (ISWC 2007) , pp. 211-224, Busan, Korea, 2007

What does SWSE do?
SWSE searches and navigates factual entities collected from over 200,000 data sources
Components:
Web-scale crawling and object consolidation
Fully-distributed RDF storage and SPARQL query processing using YARS2 (already achieved 7 billion synthetically generated triples) ‏
Advanced schema agnostic ranking
User interface with guided navigation
Features:
Ability to handle various entity types (such as people, places, proteins) and various media types
Tracking provenance of triples using context / named graphs
Search and explore the Semantic Web at:
http://swse.deri.org/

SWSE™ data flow Query Processor Index Crawler User Interface

The Sindice lookup index

The Sindice SIOC widget

SPARQLing Social Semantic Web data
Find all posts and their titles by John, using SELECT, and combining vocabularies (DC, SIOC, SIOC Types):
SELECT ?post ?title
WHERE {
?post rdf:type sioct:BlogPost ;
dc:title ?title ;
sioc:has_creator <$johns_URI> .
}

SPARQLing Social Semantic Web data (2)
Find all users that posted replies to John’s blog since January 2008, introducing the FILTER clause:
SELECT ?who
WHERE {
?post rdf:type sioct:BlogPost ;
dc:title ?title ;
sioc:has_creator <$johns_URI> .
?post sioc:has_reply ?reply .
?reply sioc:has_creator ?who ;
dcterms:created ?date .
FILTER (?date > "2008-01-01T00:00:00Z"^^xsd:dateTime)
}

SPARQLing Social Semantic Web data (3)
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
SELECT ?item
WHERE {
?person foaf:openid <$openid> ;
foaf:holdsAccount ?user .
?user sioc:creator_of ?item .
}

Parse SPARQL results
SPARQL XML
JSON:
Easiest
Many extensions (e.g. PHP5)
Many examples

Querying RDF files
Redland: http://librdf.org
Bindings: Available for PHP, Python, etc.
Example in Python:
Import RDF m = RDF.Model() m.load(‘http://apassant.net/foaf.rdf’) q = RDF.Query("SELECT ?s WHERE { ?s ?p ?o .}") results = q1.execute(model) for result in results: print result[’s']

Need more data?
Translate any data to SIOC:
Re-use SIOC tools for non-SIOC data
Semantic Pipes:
http://pipes.deri.org/
SPARQL constructs:
The “XSLT” of RDF
Translate a set of RDF data from one graph format to another
For example:
CONSTRUCT { ?x a sioc:Post . ?x sioc:has_creator ?y }
WHERE { ?x a myont:BlogElement . ?x myont:created_by ?y }

Consuming SIOC as Semantic Web data
SIOC = RDF data
Generic Semantic Web applications can be used:
RDF APIs (Jena, Redland, etc.)
RDF c rawlers
RDF b rowsers (Tabulator, Zit g ist, SIOC RDF Browser, etc. )
M ore apps : http://www.w3.org/2001/sw/SW-FAQ#tools
Customi s ed applications can provide more added value and / or better user interface s :
SIOC Explorer (faceted browsing of SIOC data)
Buxon, etc.

How can SIOC data be used?

sparql.captsolo.net/browser
SIOC RDF Browser

SIOC RDF Browser (2)

SIOC RDF Browser (3)

Demonstration of SIOC Explorer

Accessing SIOC content from multiple sources Browsing SIOC content from one source Filter by “facet” from all sources
Facet can be a direct or indirect property:
Direct
The topic of the content item
The creator of the item
The date created
…
Indirect
A geographic location of the person who created it
The gender of the person
An interest shared by many creators

Social SIOC Explorer

Browsing SIOC with Piggy Bank

Browsing SIOC with TimeLine

Browsing SIOC with TimeLine (2)

Semantic MicrOBlogging [SMOB]

Semantic MicrOBlogging [SMOB] (2)
User publishing services can ping one or a set of SMOB aggregating servers (and post on Twitter simultaneously)
Users can retain control of their own data (in RDF) through self hosting
For the server, ARC2 is used for storage / querying and Exhibit for the user interface:
Security and privacy are open issues, but can be addressed in some part by requiring OpenID authentication
At http://smob.sioc-project.org you can test client / server
Download from http://smob.googlecode.com/

Using SIOC and FOAF to represent portable data

Porting social media contributions from data providers to import services
Importing SIOC data:
A Semantic Web “building block” for portable data

SIOC i mport t ools
Importing SIOC data is easy:
Parse SIOC RDF data (e.g. using ARC2 or RAP for PHP)
Convert SIOC data to the content model of the target system :
e.g. content and other properties of blog posts and comments
Can use SIOC APIs to hold the data model
Store data in the target application :
T he most difficult part 
More info:
Uldis Bo jā rs, Alexandre Passant, John Breslin, Stefan Decker, “Social Network and Data Portability using Semantic Web Technologies” , T he 2nd Workshop on Social Aspects of the Web (SAW 2008), Innsbruck, Austria, May 2008

WordPress SIOC Importer
We have lots of producers of SIOC data, but now we need more applications that can consume it, like the SIOC WordPress Importer:
http://wiki.sioc-project.org/w/SIOC_Import_Plugin
Just as WordPress can import blog entries from various blogging systems, the SIOC importer can import any discussion posts (and comments) represented in SIOC (forum posts, mail messages, IRC chats, etc.)
SIOC data from various formats (e.g. RDFa, GRDDL) can be used

SIOC import process for WordPress
Parse RDF data (using the open-source RAP RDF parser for PHP)
Find all posts, i.e. instances of sioc:Post, which exhibit all of the properties required by the target site
For each post found, it creates a new post and all its comments using WordPress API calls
To do:
Multiple sources
Authentication
Synchronisation
SIOC import APIs

5. Leveraging semantics in Enterprise 2.0

Enterprise 2.0
Web 2.0 includes applications such as blogs, wikis, RSS feeds and social networking, while Enterprise 2.0 is the packaging of those technologies in both corporate IT and workplace environments
“ Enterprise 2.0 is the use of emergent social software platforms within companies , or between companies and their partners or customers”, Harvard Business School’s Professor Andrew McAfee
“ There are direct enterprise equivalents [to Facebook]. You can ask people the status of their projects, what they’re working on, are they travelling, things they’ve learned . All of these things would be very valuable inside an enterprise.”

Social media services that people have been using in everyday life on the Web are now entering organisations:
Blogs
Wikis
Social networking
Tagging
Microblogging
Lots of companies and products in this space:
Awareness, Mentor Scout, Contact Networks, Microsoft SharePoint, IBM Lotus Connections, SelectMinds, introNetworks, Tacit, Illumio, Jive Software, Visible Path, Leverage Software, Web Crossing, SocialText
Enterprise 2.0 (2)

Enterprise 2.0 (3)
McAfee’s “SLATES” requirements for Enterprise 2.0:
Search
Links
Authoring
Tagging
Extension
Signals
More to come in the next few years:
Gartner has identified that many more “social computing platforms” will be considered for adoption by companies during the next 10 years
Forrester Research predicts that the Enterprise 2.0 solutions market will be $4.6 billion by 2013

introNetworks

Jive Software

Issues with Enterprise 2.0
These new deployments also face the same issues that are on the Web:
Fragmented information
Blogs, wikis, RSS feeds… how can you get a global picture of a project?
Plain-text only:
“ List all the Semantic Web institutes based in Europe”
Issues with tagging:
Ambiguity, heterogeneity, lack or organisation…
The Semantic Web can offer enhanced functionality by interlinking Enterprise 2.0 data with common semantics

Semantic Web technologies can be leveraged in organisations for:
Ontology-based knowledge management
Data integration and middleware layers
Reasoning
Augmented search
See the SWEO use cases document:
http://www.w3.org/2001/sw/sweo/public/UseCases/
More than 25 case studies and use cases
Vodafone, NASA, Renault, etc.
Semantic Web in organisations

Semantic wikis:
Most wikis are plain-text only, information is difficult to re-use (e.g. “list all the Semantic Web institutes based in Europe”)
Use the wiki philosophy to build RDF(S)/OWL knowledge that can be more easily queried
Semantic tagging:
Solves the main issues of tagging: ambiguity, heterogeneity, etc.
SIOC:
Provides interoperability between applications to solve the fragmentation issue
Semantic search on the top of distributed tools
Social semantics for Enterprise 2.0

What are semantic wikis?
A wiki that has an underlying model of the knowledge described in its pages:
Semantic wikis allow to capture or identify further information about the pages (metadata) and their relations
Knowledge model available in a formal language, so that machines can (at least partially) process and reason on it
A semantic wiki would be able to capture that an "apple" article is about a "fruit" (through an inheritance relationship) and present you with further fruits when you look at apple
Some are used for personal knowledge management, others aimed at KM for communities
http://www.semwiki.org/

Structural and content metadata in semantic wikis

Semantic MediaWiki
Semantic MediaWiki is an extension of MediaWiki, the open-source wiki system powering Wikipedia:
Allows users to add structured data to the entries, turning it into a semantic wiki
Users can classify the “type” of links, e.g. making a relationship such as “capital of” between Berlin and Germany explicit:
... [[capital of::Germany]] ... resulting in the semantic statement "Berlin" "capital of" "Germany"
On the page about Berlin, users can explicitly define its population by writing:
... the population is [[population:=3,993,933]] ... resulting in the semantic statement "Berlin" "has population" "3993933"
Currently the most widely-deployed semantic wiki

SemanticWeb.org

Corporate semantic wikis in use
Ontology population is a complex task:
Knowledge engineering skills, RDF(S)/OWL modeling
Semantic wikis can ease the process
UfoWiki:
Combines:
Forms
Lightweight ontologies
Community-oriented ontology population and evolution

Issues with corporate tagging (1)
The long tail of tags:
Much valuable information, but difficult to find
Use case: EDF R&D: > 3 years, 12257 tags, 21614 blog posts
54.2% of tags used only one time, 75.77% used <= 3 times

Issues with corporate tagging (2)
Different tagging behaviours depending on expertise:
Some tags may be too generic for experts (Semantic Web) but too specific for non-experts (GRDDL)
Use case:
194 items tagged with “TF” (= Thin Film):
1% of them tagged with “solar”
< 0.5% of “solar” items tagged “TF”
Both tags are weakly related from a co-occurrence point of view
Valuable information can be retrieved by non-experts!

Tagging and the Semantic Web
More issues with tagging:
Heterogeneity: different tags, one meaning
Ambiguity: one tag, different meanings
Unrelated: no (explicit) relationship between tags
A common semantic for tags and tagging actions:
The “Tag Ontology” by Newman from 2005
tags:Tag rdfs:subClassOf skos:Concept
A “Tagging” class describes a tripartite relationship between:
A user
An annotated resource
Some tags

Going further with tagging
SCOT (Social Semantic Cloud of Tags):
A model to describe tagclouds (tags and co-occurrence)
Ability to move your own tagcloud from one service to another
Share tagclouds between services, and between users
“ Tag portability”
MOAT (Meaning of a Tag):
A model to define “meanings” of tags using existing URIs
e.g. SPARQL -> http://dbpedia.org/resource/SPARQL
Tagged content enters the “Linked Data” web
In this post, I’m using the tag ‘apple’ as dbpedia:Apple_Inc.
Collaborative approach:
Anyone can define a new meaning for a tag
Meanings are shared inside a given community

Current state of the Linking Open Data project

MOAT client for Drupal

LODr
Re-tag your existing Web 2.0 content using URIs:
Web 2.0 content -> Linked Data
LODr: http://lodr.info

Interconnecting Enterprise 2.0 services
RDF hub architecture (Tim Berners-Lee):
Add-ons to produce RDF data from existing Web 2.0 applications
Store distributed data using RDF stores
Create new applications:
Semantic mashups
Semantic search
Open architecture thanks to a SPARQL endpoint, services as plugins to the architecture

SIOC for Enterprise 2.0
A first layer of common semantics:
Lightweight add-ons, completely automated exports
Enable integration of user-generated content:
From various distributed applications

Using SIOC in collaborative working environments

Accessing BSCW spaces in BC with SIOC / WSDL

OpenLink DataSpaces
ODS provides access to SIOC instance data from a range of ODS application instances including blogs, wikis, aggregated feeds, shared bookmarks, discussions, photo galleries, briefcases, etc.

Talis Engage

An interlinked graph for Enterprise 2.0

Semantic search for Enterprise 2.0
Improving search by using semantic annotations:
But hide the RDF(S)/OWL and SPARQL complexity from end users
From plain-text to concept search

Semantic mash-ups
Integrating internal information with public RDF data from the LOD cloud:
Low-cost semantic mash-ups
e.g. geolocation services for semantic wiki data

Extending the approach
The same strategy can be applied to any community that wants to share information in a collaborative way
SWANSIOC:
Building a discourse ontology for information sharing in the context of Alzheimer disease
Joint work between DERI, Massachusetts General Hospital / Harvard Medical School in the W3C HCLS IG
http://esw.w3.org/topic/HCLSIG/SWANSIOC

6. Conclusions

Addressing the issues
Object-centred sociality makes sense:
This is the way we really use social websites
Use semantics to describe this usage, by representing objects that can be linked and reused across sites
Interlinking disconnected sites and profiles:
Leverage a “vocabulary onion” of linked semantic ontologies including FOAF and SIOC
Describe people, social networks, content items within and across sites
Providing solutions for Enterprise 2.0:
Not only the Social Web, but novel uses in organisations

Realisations of how to leverage social semantics

A vocabulary onion, building on FOAF, SKOS, SIOC, SIOC Types, DC

Disconnected sites on the Social Web / Web 2.0 can be linked using Semantic Web vocabularies

Some examples of where SIOC is already use (about 50 implementations / applications)

A list of some of these SIOC implementations
Creating SIOC data
SIOC APIs
SIOC Export API for PHP*
SIOC API for Java*
Weblog, forum and CMS exporters
WordPress SIOC Exporter
Dotclear SIOC Exporter*
b2evolution SIOC Exporter
Drupal SIOC Exporter
phpBB 2.x SIOC Exporter
Triplify*
Other exporters
OpenLink DataSpaces*
TalkDigger*
SWAML*
Mailing List Archives*
Mailing List Exporter*
Twitter2RDF*, IRC2RDF*
ZYB* (Vodafone)
Sioku (Jaiku2RDF)
gnizr*
OpenQabal*
BlogEngine.NET*, SemanticEngine.NET*
Using SIOC data
SPARQL endpoints, querying SIOC data
ODS demo server and MyOpenLink.net*
#B4mad.Net SPARQL endpoint*
Crawling and browsing SIOC data
SIOC Crawler
SIOC Browsers* and SIOC Explorer
Buxon*
Using SIOC for new data
Fishtank*
BAETLE*
RDFa on Rails*
IkeWiki*
int.ere.st
OpenLink Virtuso AMI*
Talis Engage*
Reusing SIOC data
IKHarvester, notitio.us and JeromeDL
BSCW*, BC*, Corona*
SIOC utilities
Finding and indexing SIOC data
Semantic Radar, PingTheSemanticWeb.com*
Yahoo! SearchMonkey*, BOSS
* Created outside DERI

Advice for students
Relevant journals, conferences, workshops:
Journal of Web Semantics
ISWC, ESWC, WWW, ICWSM
SPOT, LDOW, SDOW
Past events to look at:
SAW, BlogTalk, CSSW, AAAI-SSW

Coming soon!
The Social Semantic Web:
J.G. Breslin, A. Passant, S. Decker
Springer, Autumn 2009
www.socialsemanticweb.net

Thank-you… Do you want to know more?
Thanks to Uldis Bojars and Stefan Decker for their slides
The SIOC project is supported by Science Foundation Ireland under grant number SFI/02/CE1/I131 (Líon) and SFI/08/CE/I1380 (Líon 2)
The SIOC project page:
http://sioc-project.org
The SIOC W3C member submission:
http://www.w3.org/Submission/2007/02
A SIOC developer mailing list:
http://groups.google.com/group/sioc-dev
An IRC chat channel about SIOC:
irc://irc.freenode.net/sioc
A comprehensive list of SIOC applications:
http://rdfs.org/sioc/applications/
The SIOC Browser prototype:
http://sparql.captsolo.net/browser/
Semantic Radar extension for Firefox:
https://addons.mozilla.org/en-US/firefox/addon/3886

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The Social Semantic Web: An Introduction

by John Breslin

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