Slide1

Semantic Web on XML

2000/12/06

slides at:

http://www.w3.org/2000/Talks/1206-xml2k-tbl

Tim Berners-Lee
http://www.w3.org/People/Berners-Lee

Semantic Web

1. The philosophy
2. Architecture to come
3. Practical deployment

Philosophy - "Web"

• URI->Resource static mapping
• Creates navigable "space"
• Shared space = new genre of communication
• Self-describing documents
• URIs as identifiers not recipes

Philosophy - "Semantic"

• Machine processable
  • not natural language, human inference
• For data: what you can do with it
• For the future: conversion
• Declarative

Semantic links

Graphs...

...superimpose

Scaling up

from microscopic to macroscopic

Conversion of languages

• Part of the evolution of technology
• Version upgrade problem
• Test of independent invention
• Solution: common conversion semantics

Architecture

RDF+Schema layer

• Minimalist model - (thing), Class, Property
• Subproperty, Subclass
• Domain & Range
• Comments & labels

Very wide interoperability

Ontology layer

• More metainformation, such as
  • Transitive property
  • Unique, Unambiguous, Cardinality, etc
• Ontology community exists- DL, OIL, SHOE, etc. etc.
• Huge extra usage for extra functionality
• Not Turing complete

Wide interoperability & interconversion

Logic layer

• Universal language for monotonic logic
• Any rule system can export, generally cannot import
• No one standard engine - inference capabilities differ
• Many engines exist (SQL to KIF, Cycl, etc)
• Any system can validate proofs

Semantic Web bus

Practical deployment

• RDF extraction & report generation using XSLT
• RDF & Topicmaps convergence
• Many general purpose RDF engines
• Generic database -RDF tools
• Generic & specific GUIs
• W3C Standards directions in discussion

Killer App for the SWeb

Too general to be aimed at any specific application

• Ontologies - early adopters
• Catalogs on the web
• Electronic commerce transactions
• Operating across many apps (eg PDAs)
• Your favorite ....

A killer ap is what led you to discover a technology?

Thank you - Questions

slides:

http://www.w3.org/2000/Talks/1206-xml2k-tbl

Tim BL