Reasoning with uncertain information

Handling of uncertainty of various kinds is one of the key issues in expert systems. The first generation of expert systems have addressed this issue in a variety of imaginative ways. However, all these techniques have theoretical deficiencies which have been commented on in the literature. The literature also contains other innovative ideas on how this problem may be tackled. It is clear that the problem itself is very complex and does not appear to be capable of any general solution. The paper surveys the literature on reasoning with uncertain information and, in the course of doing so, articulates some of the underlying questions.