Minimal Change — A Criterion for Choosing between Competing Models

Situations are often encountered in which we are forced to make some decision although there is not enough information available. In that situation we normally use common sense to draw conclusions on the basis of incomplete knowledge. This reasoning mechanism can be regarded as meta-reasoning which chooses preferred models from several consistent models. This paper formalizes common sense reasoning of tree-structured inheritance systems and temporal projection in one framework — minimal change model. Both types of reasoning have a common mechanism — to prefer a model which changes minimally in one direction. In inheritance systems, the direction is from superclass to subclass, and in temporal projection, the direction is from earlier state to later state.