1. SOME ISSUES OF ROLE- BASED COLLABORATION Haibin Zhu, PhD Member, IEEE, Assistant Professor Dept. of Computer Science, Nipissing University, 100 College Dr., North Bay, ON P1B 8L7, Canada haibinz@nipissingu.ca

2. Introduction  Problems in current CSCW applications –Little human factors considered –Little consistent role concepts –Little practical tools for roles and for collaboration  Communications, sharing, coordinations –Group communication –View sharing and information sharing –Workflow

3. Introduction (cont.)  Roles are a powerful concept for collaboration  The basic idea of role-based collaboration –If users log into a collaborative system that can designate clearly what objects they can access with specific rights, and can also designate which users they can manage or communicate with, they can then accomplish their jobs meaningfully and efficiently. In this style, collaboration is done successfully.

4. Basic Concepts in Role-based Collaboration  An object is used to express everything in a collaborative system [8].  A human user is a person who is participating in collaboration.  A message is a command that may be issued by a human user or other objects.  An interface is a list of messages sent to objects in the system or to the system itself.  A role is a special object that symbolizes a logged human user in the system, and a role must have an interface.  We accept classes as templates of objects [3].

5. The structure of a role-based collaborative system

6. Basic Issues in Role-based Collaboration  Role assignment  Role transitions  System architecture with roles  Role-based coordination  Role-based interface design  Role-based conflict resolution  Role-based information sharing

7. Role Definition  Messages are defined by message id, receiver id and arguments; –The receivers can be divided as an object, a class or a group; –The messages can be divided as all, any and some messages;  A role can be defined a set of messages.

8. Role Assignments  Default roles and Newly defined roles  How to define a new role and its interface by requirements?  How to express a new role’s accessing of the objects in the system?  How to apply a new role in current collaboration?

9. Role Transitions  Role transition will become a very complicated process when the number of roles and the number of human users in the system grows large.  Role transitions may lead to conflicts among the access to shared objects.

10. System Architecture with Roles  Totally centralized, totally distributed, or partially distributed  Purely centralized, fully replicated, or semi- replicated  Which architecture is the best for role-based collaboration?

11. Role-Based Coordination  Roles have been used in coordination  Dynamic role specification and role transaction will help coordination more

12. Role-Based Interface Design  View sharing is supported by multi-user interface design  A role definition is also specified by interfaces  These are two aspects of the same problem

13. Role-Based Conflict Resolution  Role assignments can help to avoid conflicts  By role-based algorithms we can resolve conflicts

14. Role-Based Information Sharing  Security information sharing is important in collaboration  RBAC (role-based access control) has developed many applicable algorithms to information sharing in CSCW applications

15. Conclusion  Role-based collaboration is no doubt an interesting topic  There are still many problems open for research  They will bring us new achievements in CSCW applications