Weaving Your Own Semantic Web

1. Weaving Your Own Semantic Web Dennis Quan December 4, 2002

2. “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?

3. 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

4. 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.

5. The future of the Web • Today’s 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

6. 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? I’m willing to buy used if the cost savings is at least 50%.

7. 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

8. Agents • Programs that do things on behalf of humans Honest Joe’s Used Books $4.95 says used price A Tale of Two Cities Good condition says $10.95 price Acme Books

9. 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?

10. 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

11. Problem #2: “Grandma” • Grandma doesn’t know about SLAD-DOS: • Scripting • Logic • Agent interaction • Data types • Distributed systems • Ontologies • Schemas • Technology irrelevant if user interface cannot expose it

12. 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)

13. Grandma wants to: Tell her friends how great the toaster she bought is Find a romantic comedy on TV tonight Get a doctor’s appointment when Days of Our Lives isn’t 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 The generation gap

14. RDF to the rescue • Distributed: easily shared between systems and highly granular • Flexible: doesn’t restrict how people think about their information • Plus all the benefits of 50 years of AI and database research RDF

15. 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

16. Toys that let users play • If users don’t 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

17. 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

18. 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”?

19. Client? Server?What’s 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

20. A fantasy?

21. 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