Weaving Your Own Semantic Web

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Weaving Your Own Semantic Web

• Dennis Quan
• December 4, 2002

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Information at your fingertips

• Where are we now?
• How did we get here?
• Where are we headed?
• Who has done this before?
• Why might this not work?
• What can we do about it?
• What will the user think?

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The status quo

• The Web is a great place to find all sorts of
  information
• Weather forecasts
• News reports
• Stock charts
• Phone numbers and addresses
• TV program schedules and reviews
• Airline reservations
• and much, much more

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The origins of the Web

• Physicist turned hacker Tim Berners-Lee developed
  method for linking together network-accessible
  documents
• HTML easy to read, easy to write, easy to share
• HTTP universal transport for getting at shared
  documents via Web browsers
• Apache, Perl, et al. easy to hack together
  scripts for producing Web content en masse
• Mosaic, Internet Explorer, Mozilla, etc.

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The future of the Web

• Todays Web is great, but
• Users give them an inch they want a mile
• Vicious (virtuous?) cycle of automation
• Right now most Web content is human-readable
• 04 05 2002 part number? birthdate? price?
• Possibilities for automation are limited
• Screen scraping pre-interpreting pieces of Web
  content for use by scripts
• Semantic Web make Web content machine-readable
  in the first place

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Oh, the possibilities!

• Once content is directly interpretable, barriers
  to creative use of such content will be lowered
• Appointment scheduling
• Price comparison and negotiation
• Ontology-based search
• Examples
• Find me the cheapest French-speaking city to fly
  to in March and a hotel others found to be
  romantic.
• Schedule the meetings that must occur today for
  the afternoon and postpone the rest until the
  next 3 days.
• Where can I buy A Tale of Two Cities for the
  cheapest? Im willing to buy used if the cost
  savings is at least 50.

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Lingua franca

• Resource Description Framework (RDF) circle and
  arrow diagram method for encoding knowledge

Book
type
A Tale of Two Cities
author
Charles Dickens
price
10.95
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Agents

• Programs that do things on behalf of humans

Honest Joes Used Books
4.95
says
used price
A Tale of Two Cities
Good
condition
says
10.95
price
Acme Books
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Déjà vu?

• Flexible data representation
• Knowledge representations, ontologies and
  descriptive logic systems?
• Relational databases?
• Number crunching and deduction
• Internet price search engines?
• Perl scripts?
• Multi-agent environments?

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Problem 1 information

• Information for the Semantic Web must come from
  somewhere
• CyC approach
• Spend 25m and 20 years time
• Results in highly consistent corpus
• Problem requires 25m and 20 years time
• Distributed approach
• Piece by piece incrementally
• Each user contributes
• Problem requires tools for inputting information

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Problem 2 Grandma

• Grandma doesnt know about SLAD-DOS
• Scripting
• Logic
• Agent interaction
• Data types
• Distributed systems
• Ontologies
• Schemas
• Technology irrelevant if user interface cannot
  expose it

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Problem 3 the web monkey

• Web monkeys like
• Simple, easy-to-understand languages (e.g.,
  JavaScript, Perl, HTML)
• Granular, hands-on, reusable components (e.g.,
  CGI scripts, Web pages, Java applets)
• Ability to cycle through edit-run-debug quickly
  (e.g., with a Web browser)

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The generation gap

• Grandma wants to
• Tell her friends how great the toaster she bought
  is
• Find a romantic comedy on TV tonight
• Get a doctors appointment when Days of Our Lives
  isnt on
• See latest pictures of grandchildren

• Web monkey will need
• Distributed, P2P database with flexible schema
• Sophisticated Boolean query language
• Online representation of personal calendars and
  agent negotiation protocol
• Content management system

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RDF to the rescue

• Distributed easily shared between systems and
  highly granular
• Flexible doesnt restrict how people think about
  their information
• Plus all the benefits of 50 years of AI and
  database research

RDF
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Web monkeys like toys

• Standard RDF databases
• RDF-enabled scripting language
• Distributed agent communication layer
• Transports RDF over SOAP, POP3, SMTP, etc.
• Drag and drop ontology designers
• kind of like httpd, perl, and mysql

DB scripting
RDF
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Toys that let users play

• If users dont tell their computers things,
  agents will have nothing to work with
• PIM that automagically records calendar, address
  book, e-mail, to-do list, etc. as RDF
• Editors that can take RDF ontologies written by
  developers and intelligently allow input from
  users
• kind of like Web browsers and e-mail clients

UI components
DB scripting
RDF
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Making use of the toys

• Users must be able to ask their computers for
  their information
• Natural language schemas for mapping onto RDF
  representations
• Natural language query engines (e.g. START)
• Agents must be made easily accessible
• Users maintain their own agents much like they do
  their bookmark collections
• kind of like Google and Priceline.com

Agents search
UI components
DB scripting
RDF
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Sharing your toys

• Not all users will understand how to model data
• Let those who can share their ontologies
• Make the UI capable of finding these ontologies
  automatically
• Must also model hints or templates that give
  users suggested defaults
• UI components and agents must also be sharable
• Onto-Google?

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Client? Server?Whats the difference?

• Both users and developers create content
• Both clients and servers store information in RDF
• Agents can reside on users machines (personal
  agents) or can be distributed across the Internet
  (like Web Services)
• Truly peer-to-peer

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A fantasy?
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Exercises for the reader

• My home page
• (http//www.ai.mit.edu/people/dquan/)
• Haystack
• (http//haystack.lcs.mit.edu/)
• Semantic Web
• (http//www.w3.org/2001/sw/)
• RDF
• (http//www.w3.org/RDF/)
• Thank you for your attention