Specifying the interaction between information sources

Recently there have been proposals for sophisticated informations systems which require a number of information sources to communicate with each other autonomously. In this paper we discuss how such interactions might be specified, using performatives specified in terms of preconditions, postconditions and completion conditions, identified with respect to conversation classes. Pull specification requires additional conditions deriving from the policies and strategies of particular agents. The result is an approach to the specification of interaction between information sources which is uniform, and so permits generic handling of the different sources, but which provides sufficient flexibility to allow for different styles of conversation, and customised agent behaviour.