1. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Mobilizing the Web with DAML-Enabled Web Services Sheila McIlraith Knowledge Systems Laboratory (KSL) Department of Computer Science Stanford University (with Son Cao Tran and Honglei Zeng)

2. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Motivation The Web is evolving from a provider of documents and images …

3. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Motivation … to a provider of services

4. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Overview Problem: today’s web is designed primarily for human use. We are developing semantic markup of web services, web service users’ preferences and constraints reusable agent procedures to make services computer-interpretable, use-apparent, and agent-enabled. We are developing agent technology that exploits semantic markup to support automated web service discovery, execution, composition and interoperation.

5. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Web Service Markup Will Enable Automation of: Web service discovery Find me an airline service that offers flights to Tuktoyuktuk Web service execution Buy me “Harry Potter and the Sorcerer’s Stone” at www.amazon.com Web service selection, composition and interoperation Make my travel arrangements for my IJCAI conference trip Industry efforts growing (we are improving with DAML) Opportunity Area These are the drivers for web service markup.

6. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Semantic Markup How is DAML adding value over XML? Ontologies reuse sharing composition succinct web site markup E.g., service world-altering service purchase purchase-plane-ticket purchase-UAL-plane-ticket purchase-book... Information-providing service provide-schedule-info provide-flight-schedule-info...

7. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Semantic Markup How is DAML adding value over XML? Ontologies reuse sharing composition succinct web site markup Constraints and Rules compact representation ease of expression E.g., flight-over-3hours  movie unauthorized-web-site  unreliable-source

8. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Semantic Markup How is DAML adding value over XML? Ontologies reuse sharing composition succinct web site markup Constraints and Rules compact representation ease of expression Semantics E.g., supplier -vs- vendor due-date due-date

9. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Web Services: An Example Web service discovery Find me an airline service that offers flights to Tuktoyuktuk Web service execution Buy me “Harry Potter and the Sorcerer’s Stone” at www.amazon.com Web service selection, composition and interoperation Make my travel arrangements for my IJCAI conference trip

10. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Approach Each web site provides a set of services information providing (e.g., flight schedules, camera views) or world-altering (e.g., booking flights, home temp. adjustment) Web services are conceived as functions for execution, (~Declaratively Specified API) actions/processes for composition and interoperation. Web sites are annotated with DAML markup, describing services in terms of action preconditions and effects or in terms of processes of actions. DAML-enabled web pages

11. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 DAML Markup of Web Services E.g., service world-altering service purchase purchase-plane-ticket purchase-UAL-plane-ticket parameters: c-name, origin, dest, d-date, … preconditions: know(c-name), valid(credit-card), … effects: purchased(ticket), debit(credit-card)... rent rent-car... Information-providing service provide-schedule-info provide-flight-schedule-info... Function and action-based markup exploits ontologies: Web Service Ontologies DAML-enabled web pages Collectively they create a distributed KB of services.

12. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agents request services through brokers DAML-enabled web pages Agent Broker Web Service Ontologies Agents communicate with DAML-enabled web sites through Agent Brokers that request web services and dispatch responses. Brokers exploit the web service ontologies to assist in locating appropriate service providers.

13. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 DAML-Enabled Agents Agents are tasked by people, or by other agents. DAML-enabled web pages Agent Broker E-mail Web Service Ontologies...

14. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Generic Procedures Agents are tasked in terms of high-level, reusable “generic procedures.” “The what not necessarily the how.” Ontologies support sharing, reuse, and composition. DAML-enabled web pages Web Service Ontologies Web Procedures Ontologies Agent Broker E-mail... E.g., Travel(cust,origin,dest,date-d,date-r,purpose) Check-purpose-related-restrictions; Book-travel(origin,dest); Book-transportation(dest); Book-hotel(dest) end;

15. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Customizing Generic Procedures Generic procedures can be further constrained by DAML-defined constraints user constraints/preferences, group constraints, or instance-specific constraints. DAML-enabled web pages Web Service Ontologies Web Procedures Ontologies Agent Broker E-mail DAML-enabled personal/company constraints and prefs... E.g., Bob would like to drive if the driving distance is less than 3 hours. KSL Business air travel should be on an American carrier....

16. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Instantiating Generic Procedures Agent’s KB is automatically constructed relative to the generic procedure and constraints. KB is updated by web service responses. Deductive machinery instantiates the generic procedure wrt. constraints and world state to generate web service requests that the broker executes. KB Web Services Service Ontologies Procedures Ontologies Agent Broker Constraints & Prefs E-mail...

17. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Status DAML = First-order logic and some DAML+OIL Agent KB representation language = Situation Calculus Generic procedures representation language = Golog Deductive machinery = Prolog Agent Broker = Open Agent Architecture [SRI] Prototype agent/agent broker constructed. Preliminary ervice ontology constructed. KB Web Services Service Ontologies Procedures Ontologies Agent Broker Constraints & Prefs E-mail...

18. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Travel Example Bob Chen wants to travel from San Francisco to Monterey, departing September 2 and returning September 6. The purpose of the travel is DAML. Our Lab’s Relevant Constraints KSL Business air travel must be on an American carrier. Bob’s Relevant Constraints Bob would like to drive if the driving distance is less than 3 hours. Generic Procedure: Travel(customer,origin, dest, date-d, date-r, purpose) Book-travel(origin,dest); Book-transportation(dest); Book-hotel(dest); Inform(customer); Create-expense-claim; end;

19. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Dynamic User Interface with DAML+OIL

20. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

21. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

22. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

23. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

24. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

25. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

26. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

27. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Behind the Scenes

28. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent e-mails itinerary to customer

29. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent e-mails itinerary to customer

30. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent e-mails itinerary to customer

31. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent e-mails itinerary to customer

32. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent e-mails itinerary to customer

33. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Agent creates expense claim for customer Writing “DAML”!

34. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Summary of Key Features of KSL Work DAML Markup of Web Services, User Constraints, Agent Procedures: Computer-interpretable, use-apparent, agent-enabled services. Ontologies facilitate construction, sharing, reuse, and composition; support succinct web site markup. Markup not specific to particular agent implementation. A DAML-Enabled Agent System: DAML markup provides distributed KB for agents. Logic-based generic procedures + constraints. Procedures - general and easy to use. Constraints enable customization. Ontologies facilitate construction, sharing, reuse, composition. Procedures are verifiable wrt. certain properties. Deductive machinery instantiates procedures generating web service requests that are sent to the agent broker. Procedures & deductive machinery provide middle ground between planning & programming.

35. McIlraith - Knowledge Systems Laboratory DAML/Horus Meeting 02/16/2001 Take-Away Message Semantic Web Services are going to revolutionize B2B and E-Commerce on the Web. They will also revolutionize the way companies deal with their information and business processes. Semantic markup (DAML markup) of web services is the key enabling technology for this revolution.