Restriction of qualitative models to ensure more specific behaviour

This paper discusses methods for applying restrictions to qualitative models of physical systems in order to ensure more specific behaviour. Restriction is performed by adding constraints; directly on exogenous parameters, and indirectly on nonexogenous or dependent parameters. The former are called primary restrictions, and the latter are called derived restrictions. We show the connection between primary and derived restrictions, and how to determine the consistency of multiple restrictions. Examples are given of how a specific model is augmented using restrictions