W3C Semantic Web Activity
Marja-Riitta
Koivunen marja@w3.org
W3C Fellow - Elisa Communications
Slides available at:http://www.w3.org/Talks/2001/1102-semweb-fin/
Overview
What is Semantic Web (SW)?
W3C Semantic Web Activity
Enabling Standards and Technologies
RDF, RDF Schema, Web Ontologies
Semantic Web Advanced Development
Overview, Goals, Objectives, Highlights
Future Directions
The Semantic Web: What is it?
Many things to many people...
The Semantic Web: What is it?
An interesting bed-time story...
The Semantic Web: The original web realized
Information Management: A Proposal, Tim Berners-Lee, CERN, March 1989, May
1990, http://www.w3.org/History/1989/proposal.html
Web of relationships amongst named objects ->
The Current Web
Resources:
identified by URI's
Links:
User:
exciting world - meaning of the documents clear from
content
Machine:
very little information available - significance of the links
only evident from the context around the anchor.
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The Semantic Web - A Simple Extension to the Current Web
Resources and Links:
identified by URI's
Resources:
may be strongly typed
User:
even more exciting world
Machine:
more information available
Computers and people:
work, learn and exchange knowledge effectively
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W3C SW Activity - Goals
Design of technologies that support machine facilitated global
knowledge exchange.
Making it cost-effective for people to record their knowledge.
Focus on machine consumption
"The bane of my existence is doing things that I
know the computer could do for me."
-- Dan Connolly, The XML Revolution
W3C SW Activity - Structure
W3C SW Activity - Approach to Deployment
A lot of hard work - and a bit of luck
Foster an environment for effective cooperation and collaboration
Establish guiding architectural principles
Facilitate the design of enabling standards and technologies
Understand policy implications
Focus on short term deployment
Eye toward longer term research issues
SW Principles 1: Everything Identifiable is on SW
All resources have identity
People, places, and things in the physical world have online
representations identified by URI's.
URI's support participation, effective integration and are
contextualized in SW.
SW Principles 2: Partial Information
The current Web is unbounded.
Sacrifices link integrity for scalability.
The Semantic Web it unbounded.
Anyone can say anything about anything.
There will always be more to discover.
SW Principles 3: Web of Trust
All statements on the Web occur in some context.
Applications need this context in order to evaluate the trustworthiness
of the statements.
The machinery of the SW does not assert that all statements found on
the Web are "true".
Truth - or more pragmatically, trustworthiness - is evaluated by each
application that processes the information on the Web.
SW Principles 3: Web of Trust
SW Principles 4: Evolution
Allow effective combination of the independent work of diverse
communities.
Support the ability to add new information without insisting that the
old be modified.
Provide communities the ability to resolve ambiguities and clarify
inconsistencies.
Use descriptive conventions that can expand as human understanding
expands.
SW Principles 5: Minimalist Design
Make the simple things simple, and the complex things possible.
Enable simple applications now that plan for future complexity (eg.
Dublin Core, RSS, MusicBrainz)
Standardize no more than is necessary.
Result more than the sum of the parts
Enabling Standards & Technologies - Layer Cake
RDF Core Working Group (RDFCore)
RDF provides a common framework for representing metadata across many
applications.
Clarifies and improves RDF's abstract model and XML syntax according to
implementor feedback.
Completes the RDF vocabulary description in the RDF Schema Candidate
Recommendation.
Explains the relationships between the basic components of RDF (Model,
Syntax, Schema) and the larger XML family of recommendations.
Chairs: Brian McBride <brian_mcbride@hp.com> HP
Labs and Dan Brickley <danbri@w3.org> (W3C/ILRT)
Example - Formalized expression of simple vocabularies
"These ambiguities, redundancies, and deficiencies recall those
attributed by Dr. Franz Kuhn to a certain Chinese encyclopedia entitled
Celestial Emporium of Benevolent Knowledge. On those remote pages it
is written that animals are divided into
(a) those that belong to the Emperor,
-- Essay: "The Analytical Language of John Wilkins", in La Nación, 8
February 1942
Example - Modelling simple vocabulary
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Web Ontology Working Group (WebOnt)
Standardize means for defining ontologies that can be used on the
Web.
Builds on RDF Schema (classes and subclasses, properties and
subproperties)
Extends these constructs to allow more complex relationships between
entities (e.g.):
limit the properties of classes with respect to number and type
means to infer that items with various properties are members of a
particular class
a well-defined model for property inheritance
Input from the DAML+OIL work
supported by DARPA's DAML
Initiative
James Hendler <hendler@cs.umd.edu> chair
Example - Formalized support for ontology merging
Example - Modeling dmoz
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Example - Dmoz and My Favorites
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images
Example - Merging Dmoz and My Favorites
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SW Public Forums
Semantic Web / RDF Interest
Group
Dan Brickley <danbri@w3.org> (W3C/ILRT)
chair
a forum for W3C Members and non-Members to discuss innovative
applications of RDF and the Semantic Web.
RDF
Logic
detailed technical discussion of all approaches to the use of
classical logic on the Web for the representation of data such as
inference rules, ontologies, and complex schemata.
RDF Calendar
public forum for discussion of RDF-based calendar and group
scheduling systems
Annotation and
Collaboration
public forum for discussion of RDF-based annotation and
collaboration systems
SW Advanced Development - Goals
Explore pre-competitive, prototype ideas
Venue for liaison with research community;
Inform, be informed, nudge, be nudged
Testbed for early implementations of Working Drafts
Collaborative development environment for the Team and Members to
explore ideas together
Stimulate the development of more Semantic Web infrastructure
components
SW Advanced Development - Areas
Developer's Tools
Resource Description
Annotation, Collaboration, and Web of Trust
Access Control Rules, Logic and Proof
Calendaring and Scheduling
Work-flow and Dependency Tracking
Transformation and Extraction Utilities
Integration with XML infrastructure
SW Advanced Development - Annotation, Collaboration, and Web of Trust
Annotea : Collaborative
annotation systemAnnotations are stored on annotation servers as metadata and presented
to the user by a client capable of understanding this metadata and
capable of interacting with an annotation server with the HTTP service
protocol.
Clients include editor/browser (Amaya ) and browser plug-ins (Annozilla )
HTTP-based RDF store
Testbed for other collaboration support tools (e.g. peer review, web of
trust, recommender services, WAI, etc.)
W3C Team members: Marja-Riitta Koivunen, Ralph Swick, Jose Kahan, Eric
Prud'hommeaux
SWAD Example - Workflow
Scenario (a): Automate creation and maintenance of W3C Technical
Reports (TR) Page.
SWAD Example - Workflow
Solution: W3C Working Group Chairs assert that a document is at a
particular status by submitting an announcement to a mailing list.
<TRDocument rdf:about="http://www.w3.org/TR/xmlbase/">
<date>2001-07-09</date>
<editor rdf:parseType="Resource">
<contact:fullName>Jonathan Marsh</contact:fullName>
<contact:mailbox rdf:resource="mailto:jmarsh@microsoft.com"/>
</editor>
<of rdf:parseType="Resource">
<rdf:type rdf:resource="http://www.w3.org/2001/04/roadmap/org#WorkingGroup"/>
<contact:mailbox rdf:resource="mailto:w3c-xml-linking-wg@w3.org"/>
</of>
<status rdf:parseType="Resource">
<rdfs:label>Working Draft</rdfs:label>
<level rdf:resource="http://www.w3.org/2001/06/swamt/vocab#Recommendation"/>
</status>
<title>XML Base</title>
</TRDocument>
SWAD Example - Workflow (Announce)
Graph of formalized announcement:
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SWAD Example - Workflow (Announce, Org Merge)
Scenario (b): Also need the info of the Activity that this
document belongs to.
Solution: W3C Organizational information is merged with
Document information.
<Activity>
<name>Extensible Markup Language (XML) Activity</name>
<contact:homePage rdf:resource="http://www.w3.org/XML/Activity"/>
<includes>
<WorkingGroup>
<name>XML Linking WG</name>
<contact:homePage rdf:resource="http://www.w3.org/XML/Group/Linking"/>
<contact:mailbox rdf:resource="mailto:w3c-xml-linking-wg@w3.org"/>
</WorkingGroup>
</includes>
</Activity>
SWAD Example - Workflow (Announce, Org Merge)
Graph of combined information
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images
SWAD Example - Workflow (Announce, Org Merge)
The information presented on the TR page:
Recommendations Extensible Markup Language (XML)
Activity XML Base , 2001-07-09, Jonathan Marsh , (XML Linking Working Group)
SWAD Example - Workflow (Announce, Org, Contact, Membership Merge)
Scenario (c): AC Representative needs status of all documents that
their organization has sponsored a working group member.
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SW Advanced Development - DSpace collaboration
DSpace is a joint project of MIT
Libraries and HPDevelop a flexible digital archive to capture and distribute the
intellectual output of MIT
Explore practical SW issues in a digital library context.
explore existing RDF data stores
examine effective techniques for storing complex metadata
produce field-test proposals to be considered by other W3C
groups.
demonstrate web aggregation services based on information
syndication technologies such as RSS
Public discussion archive is
available
Future Directions of the SW Activity
Activity
Understanding relationships to similar technologies, explore
possibilies for future convergence.
Clearer ties among RDF and XML family is still required.
Better understanding between Semantic Web and Web Services is
required.
IST EU Semantic Web Initiative
Enabling Standards and Technologies
Advanced Development
Evaluation of goals and missions
More task forces
Integration with tools to support more effective means of distributed
collaborations
Cooperation with other groups working on similar issues (e.g. Sun's One
Framework, Microsoft, open source, DotGNU, etc.)
Education and Outreach
Guidelines, Demonstrations, Position papers, Articles, Presentations,
Tutorials, Tools
Conclusions
W3C Semantic Web efforts build common infrastructure
First supports simple and then more complex systems
Offers optimal reuse of data in networked environment
More formal understanding of these relationships however are still
required
The End
More information
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