The PSN tribe

AbstractThe paper reviews the history, premises, research results and applications of the Procedural Semantic Network (hereafter PSN) formalism and two of its descendants, Taxis and Telos. The primary goal for the PSN project was to develop a knowledge representation formalism which combined gracefully semantic networks and procedural representations. After an initial proposal which set out a framework for the integration of these two types of representations [1], a number of features were investigated, including the treatment of contexts, the declarative representation of slots and procedures and several others. In parallel, attempts were made to apply some of the representation ideas embodied in PSN to the task of developing suitable languages for the early stages of information system design. During these stages, the designer is concerned with understanding the problem at hand and then proceeding with the specification of an initial conceptual design of an information system that meets stated requirements. Taxis and Telos were the result of this effort. Their features are outlined, along with a rationale for the differences between the three formalisms