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Conclusion

The CONCERT architecture is based on an SPMD style of coordination where essentially a single thread of control directs the invocation and interaction of multiple processes in a distributed environment. Processes are organized in the form of "ensembles" that may either operate in leader/follower or in independent mode; different ensembles interact with each other using "beat sequences" as their basic synchronization mechanism and using a global database for communication. This form of abstraction allows also non-computer science experts to compose education sessions in a high-level language.

For the coordination of processes within an ensemble, various lower-level communication protocols and system services may be applied. This gives the necessary flexibility to hide different kinds of services with different interaction demands behind an interface that allows easy integration into the overall framework. Only the implementor of a new CONCERT instrument needs to be aware of these lower layers, the lecturer coordinating their use can just rely on the standard interface. As an example, we have described how Mathematica can be integrated for use in distributed mathematical education using the system for the presentation of hypermedia documents and for the demonstration respectively training of algorithms.

The presented implementation sketch relies on Java and compatible systems such as the CalTech Infosphere Infrastructure for providing network services and the HyperWave hypermedia system for offering distributed database services. Based on these technologies as building blocks, an implementation of the architecture with realistic efforts seems feasible in the mid-term future,