Modifyingknowledge-based systems is a complexactivity. One of its di culties is that several related portions of the system might have to be changed in order to maintain the coherence of the system. However, it is di cult for users to gure out what has to be changed and how. This paper presents a novel approach for building knowledge acquisition tools that overcomes some of the limitationsof current approaches. In this approach, knowledge of prototypical procedures for modifying knowledge-based systems is used to guide users in changing all related portions of a system. These procedures, which we call knowledge acquisition scripts or KA Scripts, capture how related portions of a knowledge-based system can be changed coordinately. By using KA scripts, a knowledge acquisition tool would be able to relate individual changes in di erent parts of a system, enabling the analysis of each individual change from the perspective of the overall modi cation. The paper also describes the implement...