The Educational Model of the UOC

1. WWG:a Distributed Infrastructure for Learning in GroupsJoan Manuel Marquès (Universitat Oberta de Catalunya,UPC)Leandro Navarro (Universitat Politècnica de Catalunya)Atanasi Daradoumis (Universitat Oberta de Catalunya) WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

2. Virtual library Learning materials Support centres Face-to-face meetings Student Tutoring action Continuous assessment Extra-academic social and professional relations The Educational Model of the UOC Flexibility Interactivity Personalisation Collaboration WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

3. Collaborative Experiences Development andexploration of 2 virtual collaborative practices: • Tutor’s coordination • Problem-based Collaborative Learning WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

4. Tutor’s coordinator in a computer architecture course • 10 tutors per semester, responsible for around 650 students • Tutors work from home. Asynchronous collaboration • tutors have to coordinate and collaborate: • Coordination to agree upon the: contents of the course; pace of study; partial examinations; evaluation criteria; kind of activities and exams. • Collaboration to: prepare exams and partial examinations; prepare new activities; decide changes on the materials. • To achieve all those coordination and collaboration tasks, they had to deal with: • Explicit communication: discuss; interchange documents; negotiate; reach agreements, making them explicit • Implicit communication: know what are doing other group members. Know if all members are participating. Know when there are new documents or participations in a discussion. • Tools: BSCW, mail. In some situations some chat or synchronous interaction WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

5. PBCL in a Software Development course • As in real live software, a project developed in groups • 17 students. Divided in 4 groups of 4 students • Mainly asynchronous communication. Also synchronous • Tool: BSCW (also mail, chat and some other synchronous interaction) • Organizational structure in 3 layer: initiating, forming and performing • Organize project, reach agreements, discuss, take decisions, share documentation, help other members, integrate software components, ... • Tutor supervises progress of the group WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

6. Some findings related to distribution • From the point of view of the members of the group • Members of a group appreciate to be aware of other members activity • Be aware of other activities prevents the feeling of isolation • From the point of view of the tutor • Tutor has to track students activity • To supervise many groups requires a lot of effort (can be overloaded) • Daily rapport functionality of BSCW well appreciated • Shared repositories to avoid inconsistencies WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

7. Learning in group at internet scale • Allow people to collaborate with other people (=group members) from anywhere, anytime • Allow members of a group to know what is happening in the group • Immediately if they are connected • Later on if they are not connected • Provide group members an easy and efficient access to awareness information (events) and to group information (objects) WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

8. Issues • Multiplicity: people may belong to several groups • Group membership may be relatively small (although there may be many groups) • Awareness: group work requires people know what others are doing • Multiple locations, mobility • Quality of service: users are offered the most accessible server from all currently available. • Degree of Connectivity: connected or not ... WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

9. Requirements (I) • Information must be accessible at any time, with reasonable quality. location not relevant: may be moved or replicated • Users need objects and events produced by other group members. Information about group actions must be accurate, up-to-date and consistent. • Scalable: large number of groups, participants, events, distance... WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

10. Now we have the Issues and Requirements, but how we structure the architecture of WWG? ...EVENTS... • Important: separation between notification of an action, and the object(s) involved. • Notifications are disseminated as Events • The central idea in WWG is the dissemination of events. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

11. Events When people do work ... • Every action produces an event (metainformation about actions). • Events belong to a group. • Events must be offered to all group members, to let them be aware of what’s going on in the group (awareness). • Events are small. ... Therefore, events must be disseminated, as soon as possible, to every group member. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

12. Event dissemination • Events provide “maximum (awareness) information” • Events provide “sense of immediateness” (if distributed synchronously) In addition... • Consistency through events • (e.g. events may indicate which/where is the latest version of an object) • Events may be used to select the best location for an object • (e.g. close to active members, several locations: replicated) WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

13. Components of the Architecture • User Agents (related to people) • Repository Agents (storage of group history: events and objets) • Meta-information Agents (group naming service; user and group administration) WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

14. User Agent (UA) Represents (stands for) users in the system. • During a session • Contains information about the user and the groups to which belong the user • Receives events and has local copy of relevant historic events and objects • Is being notified of all actions done by the local user. • Once notified, it interacts with the rest of the system to get the action processed and to disseminate the event to other group members. • Event transforming policies should be used to optimize network utilization • Receives events about actions done by other members of the group and provides this information to the user. • Transformation of events before providing them to users prevent the user from overflowing WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

15. Repository Agent (RA) Represents (stands for) storage units • Handles the storage of information (events and objects) generated in the history of groups (e.g. documents, discussions, events, users, groups, folders) • Contributes to the availability and the accessibility of the information on a potentially large scale, Handles replication and change of location of information depending on the needs of every group. • Performs transformation of events • When an user connects • For users that only want summarized information WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

16. Meta-information Agent (MIA) • Contains administrative information about users (e.g. user information, authentication information, groups to which belongs, configuration options) • Contains information about groups • Administrative information: e.g. group information, authentication information, members • Routing and dissemination information: act as a group naming service helping user agents to disseminate events among members of a group (=information to link each connected user with their present location) • Helps repository agents to decide the best location and the number of replicas needed for each object. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

17. Events. Experience at UOC shows that ... • UOC (Open University of Catalunya) is a distance university through a Virtual Campus • 3 semesters. • Tool used: BSCW • 23.566 events were generated • 80 % informative events(read event only generated once) • 20 % modify-state events • From those, only 2.2 % could cause conflict • When a person belongs to several groups or the members of his groups are very active, he gets many events and can be easily overloaded. Event transforming policies has to be applied WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

18. Improving event dissemination Many events can be generated, even thought they are small. Some techniques should be applied to ensure that the system is not overflowed (= scalable): • Aggregation: e.g. when 10 actions occur in an object, a unique event indicating that 10 actions occurred is sent • Grouping: send in the same message events that goes to the same destination • Delaying: when a lot of events are generated, postpone the sending a little while • Summarization: summary of actions done in a group. E.g. a teaching assistant monitoring a group of students may just want to know who and which kind of actions have been done and how many times WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

19. prototype + simulation • A prototype: infrastructure + browser • Implementation in Java is in development • Protocols implemented as an extension of HTTP and WebDAV • Event propagation infrastructure: Siena (java) • Unicast distribution of events on a hierarchical tree • Server: (meta-information agent + repository agent) as an extension of the Tomcat server • Meta-information agent and repository agent in one single process • Client: JavaSwing user interface • Events are XML documents (parsed with Xerces (SAX)) • Information and first version available at http://www.upcnet.es/acm1 • A simulator is being implemented: • To prove the scalability of WWG • As a way to easy refine and essay the WWG architecture and protocols WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

20. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

21. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)

22. Conclusions • WWG is intended to supportcollaboration among people pertaining to groups in wide-area networks (Internet scale). • WWG is an infrastructure. It will provide support for the construction and integration of collaborative applications. • WWG main idea is the dissemination of events. The synchronous dissemination of the events will provide: • Awareness • Sense of immediateness • Consistent distribution and replication of objects • Initial work shows the viability of WWG infrastructure, but work is under way to define events and protocols and to demonstrate their scalability. WWG: a Distributed Infrastructure for Learning in Groups Joan Manuel Marquès (UOC,UPC), L. Navarro (UPC), A. Daradoumis (UOC)