Representation of models for expert problem solving in physics

A computer program, APEX, is proposed to investigate idealized formal models representing physics problems. Two types of models are defined: canonical physical objects and physical models. During problem solving, the problem is represented as a data connection network, which is progressively augmented by these models in the form of additional network elements. APEX employs views as a representational framework for connecting the initially informal objects to the formal models of the domain. The view framework supports multiple representations (e.g., viewing many objects as a single canonical physical object), handling of incompletely specified problems, and invertibility of the views. This computational framework provides a powerful representational mechanism that allows a finite set of physical principles to be applied to a potentially infinite variety of problems. As a knowledge engineering technique, views allow general principles to be applied to a variety of objects whose representations differ