Proceedings of the Annual Meeting of the Cognitive Science Society

This paper discusses default reasoning, distinguishing generalizations associated vdth defaults from both universals and statistical generalizations. I argue that conclusions based on defaults should be reported differently frcm conclusions which do not involve default reasoning, and that however we represent than, the related inference system must distinguish default claims from other propositions and treat than differently. Two existing analyses of default reascxung are briefly criticized in light of the distinctions presented.