Evaluation of the capability of interaction

Interaction, as an important computing paradigm, is far beyond incremental technological development. Various models such as interaction machines and process algebras have been developed to help design and analyze interaction systems. However, little is reported on the computability theory of interaction, and the design and analysis still have to be performed in an ad hoc way. Hence, the question is: how to uniformly evaluate the power of interaction? Roughly, I plan to explore this question in three steps. The first is to find out a universal formal model for interaction. The second is to abstract the tasks of interaction. The third is to evaluate the capability of interaction in terms of the results of step 1 and 2. The anticipated result may be expressed as a hierarchy that extends Chomsky hierarchy from above. Possible application of the hierarchy is also presented.