Seeds of the Semantic Web
Dan Connolly,
W3C
ALA Midwinter Meeting
2000
January 2000, San Antonio, TX
Overview
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Where we are: on the verge of another revolution
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Where we came from: history and motivation
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Where we're going: opportunities and challenges
The Revolutions
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The HTML Revolution: shared information space
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The XML Revolution: culture of open exchange
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The RDF Revolution: rise of the Semantic Web
The HTML Revolution: Hypertext Goes Global
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1945: Bush imagines the ultimate research tool
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1970s: NLS, KMS, ... amazing research prototypes failed to 'cross the chasm'
of deployment
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1990: TimBL develops a minimal hypertext system for the Internet
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Web explodes out of a critical mass of content, connectivity
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No more need to "imagine a world of connected information..."
The XML Revolution: Plans
Shared costs:
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Development, Debugging
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no "bit tweezers"; helps the "desperate perl hacker"
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Structured Text: the critical features of SGML at a fraction of the cost
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Internationalized text
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Education, Training
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Basis for higher-level agreements
The XML Revolution: Plans (cont.)
XML is the ASCII of the future.
--Tim Bray
XML Files,
Oct 1998
XML is a simple data format that balances the needs of people to read/write
data with needs of machine to read/write data.
The XML Revolution: Hopes
I want my data back.
--Jon Bosak
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Self describing: DTDs, Schemas, Namespaces
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Decentralize from HTML to community markup
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Culture of Open Exchange
Stepping Back...
Origin and Goals of the Web
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Human communication thru shared knowledge
Working together: Social efficiency, understanding and scaling
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Exploitation of computing power in real life
Why W3C?
Leading the Web to its Full Potential
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Foster Evolution
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Preserve Interoperability
About W3C
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Founded Fall '94
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350+ Members
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Director, staff
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One International Consortium, 3 Hosts:
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MIT in Cambridge, MA
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INRIA in Sophia-Antipolis, France
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Keio in Tokyo, Japan
W3C Activities: What We Do
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User Interface Domain
HTML, Stylesheets, Internationalization, ...
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Technology and Society
PICS, Metadata, Security, E-Commerce, ...
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Architecture
HTTP, HTTP-NG, XML, SMIL, ...
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Web Accessability Initiative (WAI) Guidelines, Outreach, Technical review,
...
W3C Process: How We Work
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Advisory Committee
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Working Groups
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Specification Development:
Note, Working Draft, Proposed Recommendation, Recommendation
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Submissions
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Workshops, Symposia
See also: W3C Process
Looking Ahead...
XML in a Nutshell
XML balances the needs of people to read/write data with needs of machine
to read/write data.
<elementName attributeName="value">
<empty />
</elementName>
Stupid Data
<product>
<description>Blue Widget</description>
<price>1.25</price>
<size>4</size>
</product>
What's wrong with this picture?
Why Stupid Data Hurts
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Price: 1.25 what? Dollars? Pesos?
similarly for size
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Unclear relation to commerce, contracts and law:
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obligation to honor that price? for how long?
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liability for accuracy of description?
Grounding Terms in the Web
<product
xmlns:w="http://www.acme.com/2000/specs"
xmlns="http://www.ali.org/1992/commercial-code"> <!--*-->
<description>Blue Widget</description>
<price currency="USD">1.25</price>
<w:size>4</w:size>
</product>
* The American Law Institute hasn't published the Uniform Commercial Code
on the web, but the
Cornell Legal Information
Institute published a
hypertext version.
Stupid Database Exchange: Travel
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Airline sends me email from their database
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I copy/paste each of the data into my PDA
What's wrong with this picture?
Really Smart Data: RDF
<color>blue</color>
<specific-gravity>4.5</specific-gravity>
you know what that means... sort of.
RDF: Knowledge Primitives
<substance>
<atomic-number>54</atomic-number>
<specific-gravity>4.5</specific-gravity>
</substance>
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Some resource is of type substance.
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That resource has atomic-number 54.
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That resource has specific gravity 4.5.
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A substance has atomic number 54, and has specific gravity 4.5.
RDF: Graph Merging
<PDA:event>
<dc:coverage>2000-01-15</dc:coverage>
<pda:import href="http://movies.yahoo.com/showtimes?show=23ou209"/>
</PDA:event>
<movie about="http://movies.yahoo.com/showtimes?show=23ou209">
<dc:coverage>2000-01-15T2300Z</dc:coverage>
<dc:title>Life is Beautiful</dc:title>
<ucc:price currency="USD">7.50</ucc:price>
</movie>
Knowledge of Communities Large and Small
I want my machine to understand about...
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Internet Standards
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International trade agreements
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Credit Card agreements
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Local cinema schedules
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Little league schedules
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my plans for the day
notes