This paper presents an approach to the development and use of management information systems that is particularly applicable to systems with the following characteristics: - several classes of users, each of which has a different degree of sophistication - complex and changing security requirements - data exhibits complex and changing inter-relationships - changing needs to be met by information system - must be built quickly nd inexpensively - complex data validation requirements The approach is hierarchical from the user's view in that he may access the system at distinct levels, corresponding to his degree of computer sophistication. A casual user has high level primitives to work with, while an experienced user has more flexible but more detailed low- level primitives. We also have advocated that such systems be implemented in a hierarchical fashion, because this technique provides for ease of debugging, independence of hardware, and a basis for investigating properties of completeness, integrity, correctness, and performance.
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