A personal chronicle: creating better information systems, with some guiding principles

The author identifies four guiding principles which have come into play in this work of creating information systems and tools to support information systems. The first principle, open-eyes, is used to characterize information systems that remain open to new information, and consequently can compensate for changes in their mission or inaccuracies in their execution of that mission. The second principle involves abstraction levels, which in information systems are similar to differentiation in calculus. They are used to study the changes within a group of heterogeneous objects, with respect to an object type classification, so as to understand and make use of their patterns and ultimately to control the new objects of each type. The third principle, layered architecture, is used to identify a pattern of successive reimplementations of a set of functions, so as to isolate specific environmentally oriented issues. The fourth principle involves relationships, used to define associations between objects and constraints on those associations and to provide access to objects based on their associations. Reference is made to several specific projects which revealed the operation of these principles