Temporal semantics of compositional task models and problem solving methods

Task models and problem solving methods can be specified informally or form ally. In recent years various approaches have formalized the notion of task models or problem solving methods. Most modelling approaches concentrate o n the form of a task model or problem solving method rather than on their p recise semantics; a formalisation is often only a syntactical formalisation . A more precise definition of the semantics requires explication of the co ntrol of a system's behaviour. In this paper temporal semantics is defined for a compositional modelling approach to task models and problem solving m ethods. The semantics is a description of a compositional system's behaviou r; a temporal approach provides a means to describe the dynamics involved. The formalisation of the semantics is based on compositional three-valued t emporal models. The compositional structure of information states, transiti ons and reasoning traces provides a transparent model of the system's behav iour, both conceptually and formally. (C) 1999 Published by Elsevier Scienc e B.V. All rights reserved.