1. 1 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 The CYCLADES Mediator Service Dimitris Plexousakis dp@csi.forth.gr Computer Science Department, University of Crete & Institute for Computer Science - FORTH Heraklion, Crete

2. 2 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Description Functionality (general) entry point to the system Mediator component receives requests formulated by the user Satisfies requests by dispatching them to the appropriate service component Forwards results to users Serves users/communities by integrating services

3. 3 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Description Central system component supporting: user interfaces tailored to: individual users user communities / groups information retrieval ( search & browse service) information personalization (personalization service) collection building ( collection service) recommendation forwarding to users/groups (recommender service) virtual working spaces for community members (collaborative work service)

4. 4 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Overall Architecture Access Service Harvesting mechanisms Recommender Service Collaborative Work Service Personalization Service Search & Browse Service Mediator Service Collection Service

5. 5 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Functionality User Interaction Tasks User interfaces information / system description registration / profiling personalization services available to users depending on user type accessible collections depending on user type, may include virtual collections Invokes services Wraps returned information

6. 6 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Functionality Service Components Interaction Tasks dispatching requests following common protocol Search & Browse Service forward user query receive and present query result (stylesheets) issues: query interface, queries passed on as strings with no wrapping except in common communication format (?) Collection service periodic collection of descriptive metadata to determine services available issues: metadata format (adopt OAMS?)

7. 7 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Functionality Service Components Interaction Tasks Personalization Service obtain user/group profile upon login pass-on personalization requirements to other services invoke ad-hoc or on-demand mode issues: filtering at the mediator level ? Recommender Service forward recommendations wrap recommendations with query results acquire user feedback

8. 8 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Functionality Service Components Interaction Tasks Collaborative Work Service establish communication synchronize collaborative activities enable information exchange

9. 9 ICS-FORTH Dimitris Plexousakis, Pisa, February 2001 Summary Precise functional specification of Mediator Service depends on: user requirements functional specification of service components Approach: collection independence common protocol for services (e.g., HTTP) standard exchange format adoption (e.g., XML) customizable presentation (e.g., XSLT)