Formal specification applied to multiuser distributed services: Experiences in collaborative t-learning

The development of multiuser and distributed software systems faces the difficulty to program the applications correctly, in a way that guarantees the desired interaction among the users. Motivated by experiences with collaborative t-learning services (i.e. multiuser educational services over Interactive TV), this paper presents a solution to that problem, based on supplementing visual development with formal specification techniques. As a contribution to the development of interactive systems, a software process is introduced that helps defining the separate and the conjoint behavior of different users, incrementally and using highly-accessible formalisms.