Coping with change

One enduring characteristic of the law is change. To be effective in regulating the lives of those subject to it, the law must be certain, and it must be known. Yet it must be amenable to change when ita rules need revising, either because blemishes need to be corrected or because it has fallen behind social reality. For designers of legal expert systems, coping with constant change creates a major problem, since every change in the law can have repercussions on the knowledge base. In the worst case, a change in the law might require the entire knowledge base to be rebuilt. A review of the literature on the subject of legal change provided little practical guidance. The present paper is therefore an attempt to pose the problem rather more concretely than it has been treated in the paat, to summarize the attitudes to change we found in the literature, and to explain why more work is needed. Our conclusion is that although most published work on legal expert systems pays lip service to the idea that they must be designed to cope with change, the problem is still entirely open.