A computer-based supporting environment for causal understanding of large scale systems by hierarchical qualitative simulation

A framework for a computer-based training system to support acquiring deep understanding of large-scale systems through the process of forming mental models is discussed. The system provides the following functions: (1) support for constructing a simulation model based on a physical hierarchy of devices according to a user´s viewpoints, (2) support for using qualitative representation of physical parameters, and (3) support for acquiring causal information through qualitative simulation. A repetitive and transparent process for acquiring understanding is the characteristic of this supporting environment. The design concept is presented, and its implementation on a computer,including the user interface, is described. The use of the system to treat the phenomenon of step load decrease is reported