intelligent_systems - DERI

tastefallInternet and Web Development

Feb 2, 2013 (5 years and 4 months ago)


Interlinking the Social Web with

Incorporating SIOC and other semantic technologies in the Social Web, and
leveraging social interactions to enhance the Semantic Web

Uldis Boj
rs, John G. Breslin, Vassilios Peristeras, Giovanni Tummarello, Stefan


Digital Enterprise Research Institute, National University of Ireland,


One of the most visible trends on the Web is the emergence of “Social Web”
sites which facilitate the creation and gathering of knowledge through the
ification of user contributions via blogs, tagging and folksonomies, wikis,
podcasts, and the deployment of online social networks. The Social Web has
enabled community
based knowledge acquisition with efforts like the Wikipedia
demonstrating the “wisdom o
f the crowds” in creating
the largest encyclopedia
Although it is difficult to define the exact boundaries of what structures or
abstractions belong to the Social Web, a common property of such sites are that
they facilitate collaboration and sharing betw
een users, although usually on
single sites.

A limitation of current online community sites is that they are isolated from one
another like islands in a sea. Different discussions may contain complementary
knowledge and discussions, parts of the answer a p
erson is looking for, but
people participating in one discussion do not have ready access to information
about related discussions elsewhere. As more and more Social Web sites,
communities and services come online, the lack of interoperation among them
omes obvious: a set of single data silos or “stovepipes” has been created,
i.e., there are many sites, communities and services that can not interoperate
with each other, where synergies are expensive to exploit, and where reuse and
interlinking of data is

difficult and cumbersome. The main reason for this lack of
interoperation is that for the most part in the Social Web, there are still no
common standards for knowledge and information exchange and interoperation

However, the Semantic Web effor
t aims to provide the tools that are necessary to
define extensible and flexible standards for information exchange and
interoperability. The Scientific American article from Berners
Lee, Hendler and

defined the Sem
antic Web as “an extension of the current Web in
which information is given well
defined meaning, better enabling computers and
people to work in cooperation”. The last couple of years have seen large efforts
going into the definition of the foundational s
tandards supporting data
interchange and interoperation, and currently a well
defined Semantic Web
technology stack exists, enabling the creation of defining metadata and
associated vocabularies. The Semantic Web effort seems to be in an ideal
position to
make Social Web sites interoperable. The application of the Semantic
Web to the Social Web may lead to a "Social Semantic Web", illustrated in Figure
1, creating a network of interlinked and semantically
rich knowledge.

In the following sections, we will d
escribe an initiative in the area of the Social
Semantic Web called SIOC (pronounced “shock”), and we will continue by
illustrating how SIOC and other semantic technologies can benefit users and
developers of Social Web applications.

Figure 1: The Social

Semantic Web

What is SIOC?

The SIOC initiative (Semantically
Interlinked Online Communities) aims to enable
the integration of online community information. SIOC provides a Semantic Web
ontology for representing rich data from Social Web sites in RDF
. It has
recently achieved significant adoption through its usage in a variety of
commercial and open
source software applications, and is commonly used in
conjunction with the FOAF vocabulary for expressing personal profile and
networking information.

By becoming a standard way for expressing user
generated content from such
sites, SIOC enables new kinds of usage scenarios for online community site
data, and allows innovative semantic applications to be built on top of the

Social Web. The SIOC ontology was recently published as a W3C Member
Submission, which was submitted by 16 organizations

The SIOC ontology

The ontology consists of the SIOC Core ontology

(consisting of 11 classes and
53 properties) and two ont
ology modules: SIOC Services and SIOC Types.

Figure 2: The main classes and properties in the SIOC ontology

The SIOC Core


defines the main concepts and properties required to
describe information from online communities on the Semantic Web. The
terms in the SIOC Core ontology are shown in Figure 2. The basic concepts in
SIOC have been chosen to be as generic as possible, thereby allowing us to
describe many different kinds of user
generated content.

The SIOC Core ontology was originally crea
ted with the terms used to describe
based discussion areas such as blogs and message boards: namely

. Users create Posts organized in Forums which are hosted on
Sites. In parallel with the evolution of new types of social websites,
concepts became subclasses of a higher level concepts

data spaces
, a place where data resides
), containers (
, used for
grouping items together
) and content items (

which were added to



SIOC as it evolved. These
classes allow us to structure the information in online
community sites and distinguish between different kinds of objects. Properties
defined in SIOC allow us to describe relations between objects and attributes of
these objects. For example:


property links reply posts to content that they are
replying to;



link user
generated content to additional
information about its authors; and


property points to a resource describing the topic of conten
items, e.g. their categories and tags.

The high
level concepts


are at the
of the SIOC class hierarchy,
and most of
other SIOC classes are subclasses

of these
. A data space (
a place where dat
a resides, such as a
site, personal desktop, shared file

space, etc. It can be the location for a set

of content
Subclasses of

can be used to
further specify typed groupings of

in online communities.
The c

is a high
level concept for content items and is used

for describing
created content.

Usually these high level concepts are used as abstract classes which other SIOC
classes can be derived from. They are needed to ensure that SIOC can evolve

and be applied to specific domain areas where definitions of the

classes such as


can be too narrow.

For example, an
address book
, which describes a collection of
social and professional contacts
type of

but it is not
the same as
a discussion forum.
We will now
describe some
of these high
level SIOC concepts from the “SIOC
Types” ontology module.

SIOC modules

A separate SIOC Types module defines more specific
es of the SIOC
Core c
oncepts which can be used to describe the structure and various types of
content of
Social Web
sites. This module defines subtypes of SIOC objects
needed for more precise representation of various elements of online community
sites (


is a

), and introduces
new subclasses for describing different kinds of
Social Web objects in SIOC. The
module also points
to existing ontologies suitable for describing
details of
these objects (


may co
, described in
detail using the Review Vocabulary). Examples of SIOC Core ontology classes
corresponding SIOC Types Module
es include:


AddressBook, AnnotationSet, AudioChannel, BookmarkFolder, Briefcase,
ChatChannel, MailingList, MessageBoard,


BlogPost, BoardPost, Comment, InstantMessage,
MailMessage, WikiArticle

Community sites typically publish web service interfaces for programmatic search
and cont
ent management services (typically SOAP and/or REST). These
services may be generic in nature (with standardized signatures covering input
and output message formats) or service specific (
where service signatures are
unique to specific function


as can be seen in
Web 2.0 API

usage pattern
SIOC Services ontology module allows one to indicate that
a web service is associated with (located on) a

or a part of it. This
module provides a simple way to tell others about a web se
rvice, and should not
be confused with web service definitions that define the details of a web service.

used to relate a

to its full web
service definition (

in WSDL).

lationships between SIOC and

other ontologies

Figure 3: Relations between the SIOC, FOAF and SKOS ontologies

One of the best practices of the Semantic Web is the reuse of existing ontologies
and vocabularies, leading to better data interoperability. The SIOC ontology
follows this p
ractice by reusing the FOAF vocabulary to describe person
data and the Dublin Core (DC) vocabulary to describe properties of SIOC content
items. Figure 3 gives an example of some of the relations between SIOC and
other vocabularies. A person (descr
ibed by
) will usually have a
number of online accounts (
) on different online community sites. They
use these accounts to create content (

). The class

is a subclass of

and the

property links a person to his or her online accounts. SIOC content items (shown

objects on Figure 3) are described using properties from SIOC, FOAF
and Dublin Core.
By using FOAF to point to multiple social media site accounts
stered to a user and using SIOC to express user
generated content on these
sites we can aggregate the content created by a person all across the Social

Topics are usually present on the Social Web as categories and tags assigned to
content items and a
re represented in SIOC using a

property. SIOC
does not enforce the values of

to be in a particular ontology (apart from
the value being a URI) and leaves it up to information system architects to
choose the most appropriate ontology t
o represent topics in each case. One of
the approaches, illustrated in Figure 3, is to use the Simple Knowledge
Organization System (SKOS) schema to represent topic hierarchies and the
relationships between them.

documents for
more detailed
information on

between SIOC and other RDF ontologies.

What SIOC is not…

SIOC aims at the representation of information of online community sites and
human communication. However, in contrast to other representation

(e.g. OWL Time
) SIOC is not aiming at an axiomatization of a domain. The
SIOC ontology was deliberately designed to capture existing information that is
mostly present in current Web information systems and to p
rovide a low entry
barrier for users and developers. The design of SIOC allows one to export
information from many sources by relatively simply means, and thus to generate
a critical mass of information, leading quickly to the Web community adopting
providing additional exporters and writing applications. SIOC is aimed at a
minimal consensus of a given domain, rather than a complete specification.

Sidebar #1: Useful SIOC resources

Here are some useful resources for finding out more about the SIOC init







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A comprehensive list of SIOC applications;

The SIOC Browser prototype;

Semantic Radar extension for Firefox;

US/firefox/addon/3886's namespace statistics page lists SIOC as
their fourth most used namespace out of 4
. According to this service,
there are more than
,000 RDF documents using SIOC on the Web;


Sidebar #2: Some recent SIOC applications

being used by companies in a variety of application domains.
For example, OpenLink's Data Spaces product provide access to SIOC instance
data (“
think open social graph++")
from a
range of application

including blogs,
wikis, aggregated feeds, shared bookmarks, discussions, photo galleries,
briefcases (e.g. WebDAV file servers), etc. Engage is a community information
application from Talis that
SIOC in its schematics with S
KOS for
knowledge organization and FOAF

for person description
. The Seesmic “video
microblogging” service has also adopted the SIOC ontology as one of their open
platform formats. Talk Digger, a web service from Zitgist LLC that helps people to
find, follo
w and enter conversations on the Web, exports
all of
their data using
SIOC. And ImageMatters LLC have recently announced a new
social bookmarking and mash
up application called gnizr, that exports saved
bookmarks using SIOC in combination with
a tag ontology.

here are
other open
source applications of SIOC coming
web developer community
. OpenQabal, an open source social networking and
collaboration platform is supporting SIOC, allowing Roller, JavaBB and other
component appli
cations to become part of the SIOC
sphere. SIOC descriptions
of fora are also being used for teaching and learning, for example, in the Fishtank
project for Faculty Academy which leverages the structure and searching power
of RDF.
a wiki for kno
wledge engineering, allows discussions
represented using the SIOC ontology
(following a forum style with threaded
views) to be attached to wiki pages. SWAML, the Semantic Web Archive of
Mailing Lists, uses SIOC as its base ontology. The project also includ
es Buxon, a

visor written in PyGTK.

Finally, a third
RDF exporter for
Twitter microblog


has been created that uses SIOC (for
representing all
microblog entries) and FOAF (for describing the people).

enabled applications
and tools

SIOC gives different online community sites a common format for expressing
their data in a rich, interlinked form. This interconnection of Social Web content
using Semantic Web technologies can lead to many interesting possibilities on
the indivi
dual and community level. With the data represented in SIOC, various
browsers and applications taking advantage of this information can be built on
top of SIOC.

This section describes a food chain of such applications, starting with tools used
to generate
SIOC data from online community sites and concluding with
applications for browsing and reusing this information.

The SIOC food chain

Figure 4: The food chain of applications producing, collecting and consuming SIOC

Figure 4 shows some application types
in the SIOC food chain, illustrating where
SIOC data is being produced, collected and consumed. This is not exhaustive
but it does cover the majority of SIOC application types available today

Producers of SIOC data include: various add
ons and modules fo
r applications
that reuse and build on existing internal functions to export SIOC data in RDF
format (e.g. the SIOC exporters for

or Drupal); sources of semi
structured data or queryable APIs that output data in formats that can be
converted to S
IOC and augmented with other RDF data (e.g. SWAML for mailing
list mailboxes, the Flickr2RDF tool, and Sioku which leverages the Jaiku


microblogging API); applications that natively store semantic data and use SIOC
as one of their representation formats (e
.g. Talis Engage); and schema mapping
tools that directly access MySQL or other relational database stores

default application access methods

to generate SIOC metadata (e.g.

Data Spaces). To aid with the production of SIOC data from
new applications,
reusable data export APIs have also been created for PHP, Ruby on Rails and

The SIOC data produced by these applications may either be discovered,
collected, stored and/or indexed in an intermediary step, or may be consumed

by end
user applications
. Collectors can include: Semantic Web
spiders ("scutters") or crawlers specifically tailored towards gathering SIOC data,
which may store SIOC instances from multiple sources in a single data store
(e.g. SWSE, Swoogle, Zitgist, and the SIOC Crawler); and indexers which will
store lists of where SIOC data instances are available from (e.g. Sindice and

Consumers of SIOC data include: generic browsers for RDF data (e.g. Tabulato
and Disco) or those that are customized towards the display of SIOC data (e.g.
the SIOC Explorer and Buxon); extensions for web browsers that detect the
presence of SIOC and other RDF data, for pinging data indexing services or for
reusing / clipping of
community contributions elsewhere (e.g. the Semantic
Radar); applications that can import SIOC data, for example, for portability of
data contributions between user accounts on different systems or for migrating a
community from one site to another (e.g. t
he SIOC importer for
); and
applications with visualizations oriented towards SIOC linked data graphs (e.g.
Alexandre Passant's "SIOCal network" browser

that displays SIOC comment
structures in terms of a network of their creators).

Generating th
e data

SIOC export tools are a class of application which produce SIOC RDF data from
online community sites (blogs, wikis, forums, etc.), often implemented as plug
to the specific content management system used on a site. By enriching social
sites with SIOC RDF exporters, high
quality data can be
automatically created without the need for screen
scraping and having to
reconstruct the relations from the information visible on web pages.

SIOC export plug
ins are available for several common cont
ent creation
platforms. An important property of these SIOC exporters is that information
about every content item on a site is represented in RDF, making all the main
information contained within a site available in RDF and ready for reuse. Most
SIOC expo
rt tools also use RDF auto
discovery links (i.e., a link to an RDF
document which is inserted inside the HTML HEAD element of web pages on the


site) that enables automatic discovery of this content by tools such as the
Semantic Radar plug
in for Firefox


SIOC export plug
in is one the most popular SIOC export tools,
developed for a popular blogging platform. Similar export tools have been
developed for a number of different online community site engines
were developed as a part of

the SIOC project in order to lower the barrier for
entry and to help people who are not familiar with the Semantic Web to write
SIOC exporters for their community sites. An example of such a library, the SIOC
API for PHP, provides an easy way to manipulat
e SIOC data through PHP
objects and methods, and renders the data into RDF/XML. The API creates and
exports SIOC concepts about authors (

), posts and
comments (

), and the structure of the website


Reusing SIOC data

As the Social Web begins to generate more SIOC data, this information can be
reused by consumers of SIOC data, e.g. to provide better tools for finding related
information across community sites or to transfer rich in
formation about content
items between online community sites. The pilot implementation of a SIOC
import plug
in for WordPress

is an example of an application for reusing SIOC
data between social media sites.

This plug
in can be added to the WordPress blo
g engine and demonstrates how
SIOC data may be used by regular blog users (e.g. via an admin user interface).

A user begins by supplying the URL of some SIOC data. The plug
in then
retrieves SIOC data from this URL, extracts all the content items and posts

to the blog. While the pilot implementation only processes one SIOC data file at a
time, it can be easily extended to mirror all content from a blog or forum site.

Tools like this SIOC import plugin enable us not only to transfer content items
en the same type of sites (e.g. blogs), but also between different types of
social media systems (e.g. between a mailing list, expressed in SIOC using
SWAML, and a blog). By combining data export and data import tools for SIOC,
we enable various scenarios
for data portability of social media contributions
(described later), allowing people to save their contributions and move them
between different online community sites.

Faceted exploration of SIOC data






The SIOC Explorer

aggregates data from various onlin
e community sites and
allows users to browse and explore all disparate information in an integrated
. The core of this application is BrowseRDF

a faceted navigation
system for RDF data which is domain independent an
d provides a generic view
of all RDF data associated with SIOC concepts (e.g. the

between authors and posts). The application aggregates SIOC content into a
local RDF store and provides various ways to view the content and associated
ta. The start screen allows one to choose from a list of available
with data coming from SIOC
enabled systems such as online community forums,
blogs, mailing lists, etc.

Figure 5: Faceted exploration of SIOC RDF da
ta in the SIOC Explorer

When viewing posts from an individual forum or a group of forums, the user is
presented with the list of posts in a reverse chronological order. Each post is
summarized (see Figure 5) and can be expanded in order to read the full co
Clicking on the creator of a post shows all posts (including comments and
replies) written by this person, across all forums; clicking on a topic shows all
posts tagged with this topic, again across all forums. In contrast to ordinary feed
such lateral browsing works across all different types of community


forums that can be described in SIOC: clicking on the user “Elias Torres” will not
only show his blog posts, but also his emails and contributions to IRC.

Finally, a generic faceted navig
ation interface is offered on the left
hand side,
displaying relevant facets that are not already shown as a part of the default
browsing interface. Facets are built dynamically at view time and will show the
properties and values derived from the actual d
ata, also displaying properties
which may not be known at the system design time. Some facets (like the year)
contain only "simple" values while complex facets, such as maker or topic, can
be further expanded to see subsequent sub
facets (as shown on the b
ottom left
of Figure 5). Application developers can customize the facet navigation to their
needs and may choose to exclude or include certain facets, or choose to exclude
certain advanced operators such as the inverse join or the existential join.

C Explorer is built on the Ruby on Rails framework for web application
development and uses several components for consuming and processing
Semantic Web data: ActiveRDF for mapping RDF data onto programmatic
objects; BrowseRDF, a faceted browsing engine th
at enables navigation of large


datasets without domain
specific navigation knowledge; and the
SIOC RDF crawler that crawls, extracts, normalizes, and integrates SIOC data
from various community sites.

Exploring people’s social connections via

Figure 6: Object
centered sociality: connecting users via content items created by them

The term “object
centered sociality”

refers to a hypothesis that people are
connected through the objects that they create and collaborate on. In the Social
Web, people are related through user
generated content and annotations. Figure
6 shows a conceptual illustration of this idea using a model of content “circles”


created by a person via multiple online accounts
. Connections
are formed
between these circles by people creating similar content or using similar

For example, Bob and Carol are connected via bookmarked URLs that they both
have annotated and also through events that they are both attending, and Alice

Bob are using similar tags and are subscribed to the same blogs. SIOC and
FOAF can be used together

to describe the objects in this social network of
users, with FOAF describing information about the people and SIOC describing
user accounts and their use
generated content. All this information, integrated
across the Social Web, allows us to build up a picture of all the objects that a
user has created, interacted with and commented upon across different social
media sites, from which the links between th
e users themselves emerge.

Figure 7: Aggregate view of information about a person in the Social SIOC Explorer

The Social SIOC Explorer

is an extension of the SIOC Explorer which allows
us to see and explore social relatio
ns or the Social Web manifested via user
generated content. The rich data structure, including links between an original
post and its replies and links between a post and additional information about its
author, is collected from producers of SIOC data. Th
e Social SIOC Explorer can
use this information to mine relations between people on the Web, for example,
to find a set of people who have participated in a discussion with or who have
commented upon the content created by certain user (see Figure 7).


In a
ddition, this application contains an additional component that performs social
network analysis using information about the content created by users, extracting
social context information from the SIOC data and allowing visualization of this
information i
n the user interface.

SWPop: live, embeddable SIOC aggregation

SWPop is a framework for creating semantic data
powered plugins which can be
embedded in various web applications. It demonstrates a synergy of applications
for both the collection and consumpt
ion of SIOC data. Using SWPop, some
powered widgets have been created for
WordPress blog engine which
enhances the blogging platform with information derived from harvested SIOC
data. When the SWPop plugin is activated, the web application is popu
lated with
popups showing a summary of information and discussions from the entire
sphere” (all available sources of SIOC data). The SWPop
application uses the Sindice Semantic Web search engine

(“Indexers of SIOC
Instances w/o Full Storag
e” in Figure 4) to locate relevant RDF information

Let us look at an example of a forum dedicated to work opportunities for experts
in web technologies. Human resources are interested in hiring a Semantic Web
consultant a
nd post a request for this position. Many people reply with questions
and proposals. With the SWPop plug
in, a user can click on an author’s name,
e.g. John, and see a popup window with topics and posts recently created by
John anywhere on SIOC
enabled onl
ine community sites (Figure 8). The user
can then navigate across his posts and restrict results to a given topic, if needed.
Similar cross site navigation is possible starting from links which are mentioned
in a post or from topics (keywords). This is not

only interesting for casual
background checks, but also introduces a concept of reputation portability by
allowing others to quickly assess the value of John’s statements given his
previous distributed online activity.

Technically, the SWPop plug
in for w
eb applications operates as follows:


SIOC RDF data export functionality is added to the site,


When a new post is created, WordPress generates a ping towards the
Sindice Semantic Web search engine,


The rendered web page is enriched by adding a microformat t
hat contains
a SHA1 hash of the author’s email and the SWPop JS (JavaScript) code
which will skin the microformat with an SWPop information popup.

When the page is loaded, the SWPop JS will detect the microformat and perform
an AJAX call to the backend SWP
op application. The backend application is
based on the Sindice Semantic Web search engine, which keeps a frequently
updated index of all the RDF resources on the Semantic Web. Sindice provides a


public API which provides various ways for locating RDF sour
ces, e.g. by text
keywords, by URI or by inverse functional properties, such as the FOAF SHA1
hash of an e
mail address (
) in this case.

The SWPop backend uses these APIs to locate RDF information related to the
author of the post, based on the

SHA1 hash of his e
mail address. The
information returned may include articles and comments made by the poster
across the SIOC
sphere (with data about posts such as topic, date, subject,
etc.); details
about the poster (e.g. photos) from other sources,
e.g. FOAF profile
files; and social network information.
SWPop collects all this information into a
named graph repository on top of which analysis and queries are performed.

Figure 8: SWPop shows John’s recent activity on SIOC
enabled online community


Based on results of the analysis, a speech balloon with posts and other
information about the person, collected from across the Social Web, is generated
and added, e.g. next to the name of the poster on the web page. When a visitor
clicks the balloo
n, the server will create an aggregate of post titles, sorted by
date, along with recent topics about which the poster has been writing about from
all sources of SIOC data. It will then send this data to the SWPop JS using

A benefit of applications
like SWPop is that very little effort is required to install
them and to tap into the existing vault of information described in SIOC and other
Semantic Web vocabularies. The client
side part of the application is very
lightweight and all the “heavy liftin
g” is done by the SWPop backend and by large
RDF indexing applications such as Sindice.

ed initiatives

SIOC is being promoted by various working group initiatives and is also being
tailored towards various community domains (including social network p
collaborative work spaces, life science discourse, etc.).

We will now describe some initiatives that have adopted and are using SIOC,
illustrating how a variety of communities see value in SIOC and are applying it to
their use cases.

Data porta
bility using SIOC


working group

was recently established to look at ways in
which data could be ported from one social media service to another.
It aims to
document the best practices for integrating existing open standards and
ls to enable end
end data portability between online tools, vendors,
and services. A goal of the DataPortability group is to enable users to move,
share, and control their identity, photos, videos and al
l other forms of personal

One of the sample
data portability scenarios involves using the YADIS
communications protocol to discover an identity for a particular person, which
then returns a YADIS/XRDS document indicating which identities that person
prefers to use and what services those identities
are held on. Then, the WRFS
abstraction model can be used to find out what containers the returned identities
hold on those services




Figure 9: Accounts held by a user on various object
centered social networks

SIOC is an ideal representation method for

describing all content items created
by a person (via their user accounts) on various social media sites and the
structure contained therein. A combination of the FOAF vocabulary and SIOC is
well suited to describe a relation between a person and multiple

social media site
accounts owned by this person. FOAF is used to express a person’s social
network profile and points to relevant SIOC data about their user accounts and
the content created using them.

In Figure 9, Bob holds user accounts on various socia
l websites (two shown for
clarity, but there could be many more), and via those accounts he creates
content items on those sites (usually within containers of some sort, e.g. in a
bookmark folder, personal blog, message board or image gallery). He should b
able to port not only his social graph (in this case, his connections to Alice and
Carol), but also his personal containers / sets of content items and perhaps even
associated comment replies. The vocabulary terms are shown in dark grey:
, etc.

SIOC is more that just a way to represent personal containers of data. Another
task set by efforts such as the

workgroup is to explore methods
for porting not just small user
centric sets of data but whole sets of community
a. SIOC was initially created to provide a way to describe the content from
online communities (mailing lists, message boards, etc). While it was soon used
for people's blogs and more recently for other personal sets of Web 2.0
content items, it has t
he concepts needed to describe the structure and contents
of a community site as a whole. If someone runs a community site, and they
decide that they want to port their group from one place to another, SIOC can be
used to describe the structure and content

of the existing community site in order
to re
create it on a different information system.

One challenge for DataPortability is
mapping of different data standards. As
this initiative may use related but different data representation methods for
us scenarios (e.g. XFN / hCard and FOAF), the issue of mapping between
these formats needs to be addressed.
It is


that existing work from the
Semantic Web domain (ontology mapping, GRDDL) will provide a significant
contribution to addressing this que

For this initiative, SIOC is an open standard for describing user
created content
and thus enabling data portability. As it based on Semantic Web technologies
such as RDF, SIOC data can be easily mixed together with other RDF data
formats (e.g. DOAP
, Review, etc.) which may be required by more specialized
community sites.

Interlinking Collaborative Work Environments

In the area of Collaborative Work Environments (CWE), platforms like Lotus
Notes, Microsoft SharePoint and BSCW currently p
rovide integrated work spaces
to support the knowledge worker inside the enterprise. During the last 20 years,
the main driver for the development of such platforms has been the need for
interoperability amongst a large number of applications that were ini
tially built
separately to support specific work tasks, e.g. separate tools for project and
document management, calendars, forums, mailing lists, etc. These CWE
platforms integrate CWE tools and related information, and are used to enhance
ion knowledge storage and processing.

With the introduction of these CWE platforms, the interoperability problems were
adequately addressed internally. However, at the inter
organizational level,
problems remain. These platforms remain informational silos
as they are legacy
and isolated systems that cannot communicate with the rest of the world. From
an organizational perspective, this creates insurmountable barriers to the
exchange of information with peer organizations, while from the perspective of
the s
ingle user, it creates a situation whereby information that may exist in
separate systems cannot be combined and must be collected and processed

The case of an e
professional (e.g. engineers, lawyers, researchers) who works
at the same time on a
number of projects that are supported by different CWE
platforms is quite interesting. How can they find a comprehensive list and links to
all documents (and/or posts) that have been uploaded (and/or edited) during the
last week in all the projects (and pl
atforms) that they may be involved in? And
how can they identify links to resources categorized for example as “architecture”
that may be stored in all of these different platforms?

Currently, the Ecospace Integrated Project is addressing these types of
oblems. The SIOC ontology has been adopted in the project to provide the
basis for much
needed multi
platform integration and to allow cross
querying and access to this semantically
interlinked information
. This ha
occurred in three stages:

First, concepts that exist in the CWE domain and appear in the involved

namely, BSCW and Business Collaborator (BC)

mapped to the SIOC ontology (e.g. document, folder, user, post). That
was feasible since SIO
C has been developed to cover online
communities, a domain quite related to CWE. In this way, SIOC provides a
language for the CWE domain.

Then, SIOC exporters were developed by the consortium both for the
BSCW and the BC platforms. These tools, based

on the conceptual
mappings created in the previous stage, annotate the internal data and
export them as SIOC RDF data. Since these tools use the same SIOC
ontology, the internally
kept data acquires the same semantics and
becomes understandable and proces
sable by any RDF
based application.

Finally, a specialized SIOC4CWE explorer has been developed for
navigating and querying aggregated SIOC data from heterogeneous
shared workspaces in a unified way. This provides the user with a single
interface to query
all the projects he or she participates in regardless of
whether they are stored in BSCW, BC or any other platform.

As a result, queries like those presented above can be answered. The user can
have direct access to documents, posts, calendar, contacts and

any other kind of
resources that were previously “locked” inside each separate platform. Following
this approach, any CWE platform can become interoperable with the others and
accessible by the SIOC4CWE explorer from the moment it exports SIOC
annotated d
ata. Developing a SIOC exporter is a comparatively easy task that
can potentially give a huge ROI for favorite CWE platforms, as it provides a
semantic bridge to the outer world. Currently, a SIOC exporter for SAP

is under consideration in the co
ntext of the same project.

zen and the Art of Scientific Community Maintenance

The bio
zen initiative

is an attempt to represent data, information and
knowledge from research in all facets of life sciences on the Semantic Web. The
goal of this projec
t is the unification of information that is now scattered through a
multitude of different data structures, exchange formats and databases.
As part
of this, t
he Semantically
Interlinked Scientific Communities

(SISC) effort aims to



improve how scientific d
ata and knowledge is currently being represented and

zen and SISC uses SIOC, FOAF, DC, Creative and Science Commons, OBO
and HCLS ontologies and technologies as its foundation. SIOC is adapted by
authors of this initiative
for the repres
entation of basic scientific discourse in
scientific publications or on the web.
According to Matthias Samwald, creator of
these initiatives, SIOC was chosen one of the base ontologies for this effort since
it provides "an excellent tool to describe scient
ific discourse in a practical, web
centric manner".

Future “shock”

Following on from the successful dissemination of the SIOC ontology and its
implementation in over 40 modules and applications, the existing work on SIOC
will be extended to look at more sp
ecific application domains. The SIOC project
has a stable ontology and a good foundation of tools using it, but we now need to
figure out what the requirements are in particular domains, whether it be
interlinking real estate communities or extracting pers
onal skills from user
generated content. A number of use cases are being targeted to see how SIOC
needs to be augmented with some domain
specific terms. Some of these
domains of interest include facilitating customer health support groups (patient
from peers on the Web), providing structured representations of
professional scientific discourse, and modeling / navigating interactions in pre
legislative consultation processes.

An interesting dimension is the application of SIOC in CWE platforms. The i
purpose of SIOC was to link open online communities on the Web. In the CWE
case, SIOC is being used in a fundamentally
different environment: linking
legacy, closed and proprietary systems. We intend to reuse this experience for
applying SIOC
solutions in other similar areas. The more general area of
Enterprise Application Integration (EAI) seems to be a challenging candidate
where interoperability issues are of critical importance.

The SIOC ontology is already used together with vocabularies s
uch as FOAF,
DC and SKOS. We expect SIOC to act as a "crystallization point" (shown in
Figure 10) in bringing various domain ontologies together in order to better
describe user
generated content both on the Social Web and in enterprise
environments. SIOC
provides a framework to which further details about content
items can be attached. If additional information, e.g. embedded in the item or
retrieved using NLP techniques, is available about a content item, this
information can be described in RDF and attac
hed to existing SIOC data about
this item.

We will also investigate Social Semantic Web solutions for enhancing discussion
topics on social software systems such as forums, blogs, wikis and podcasts with
semantics, to yield what we may term "semantic diale
ctic topics". It will build on
the SIOC project, the SALT semantic authoring effort
, and existing
argumentative discussion efforts such as IBIS and Compendium, to create a
structure for defining the topics and argumentative nature of future discussions

well as providing methods to attempt a classification of existing topic
discussions. The application domains of scientific discourse (see SISC above)
and legislative debate are of particular interest here.

Figure 10: SIOC, FOAF, SKOS and DC as a "crysta
llization point" for domain specific ontologies


Systematic access to knowledge is critical for solving today’s problems

on an
individual, organizational as well as on a global level. To develop new solutions
and enable innovation, networks are


networks of people and
organizations having access to networks of knowledge. Although knowledge is
inherently strongly interconnected, this interconnectedness is not reflected in
current information fabrics, and thus these fabrics are not opti
mal for supporting
the development of solutions and innovation. The lack of interconnectedness
hampers basic information management and problem
solving capabilities, like
finding, creating and deploying the right knowledge at the right time for problem
ving and collaboration.


The combination of Semantic Web and Social Web collaboration technologies
can be directed towards a universal collaboration and networked knowledge
infrastructure, enabling knowledge management capabilities as expressed by
es like Vannevar Bush

or Doug Engelbart
. For the largest part,
their ideas remained a vision for far too long since the necessary foundational
technologies were not yet invented

ly speaking, these ideas were
proposing jet planes when the rest of the world had just invented the parts to
build a bicycle. Starting with the Semantic Web and the Social Web, the
foundations to make these visions a reality now exists. One of the most pre
vocabularies enabling collaborative knowledge sharing that is growing on the
Semantic Web is the SIOC ontology

aiming at semantic
interlinking of online
community sites.



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We would like to acknowledge the co
ntributions of Fabio Corneti and Adam Westerski
on SWPop, and of Eyal Oren and Benjamin Heitmann on the SIOC Explorer. This work
has been funded by Science Foundation Ireland under grant number SFI/02/CE1/I131,
and also by the Ecospace EU project with numb
er FP6
5 35208.