GAUSS: A Generalised Approach to Updating Scanner Strategies

Abstract

This paper is concerned with a systematic approach to knowledge base maintenance using an application in magnetic resonance (MR) imaging. The aim is to allow an expert to make changes to the knowledge base, always leaving it consistent and correct. The changes may be necessary for three reasons: (a) to correct any errors found in the knowledge base (b) to accommodate new research findings and (c) to adapt the knowledge base to the individual preferences of different experts. The types of changes considered range from minor modifications of the menu driven user interface to the introduction of new concepts and associated facts and production rules. In this context the paper discusses the following points: (a) Basic design and functionality of the expert system, (b) Modification of the menu system, facts and rules; consistency checks and on-line help, (c) Explanation facilities to help explore the implications of changes, (d) Debugging and trace facilities to follow the reasoning of the system, (e) Testing procedures to ensure the correctness of the modified knowledge base.