Restriction of Qualitative Models to ensure more Specific Behavior

This paper discusses the restriction of qualitative models of physical systems in order to ensure more specific behavior. Restriction is performed by adding constraints : (i) directly on exogenous parameters, and (ii) on non exogenous or dependent param eters . The former are termed 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 to show how a specific model is augmented using restrictions .