The aim ... is to provide a clear and rigorous basis for determining when a causal ordering can be said to hold between two variables or groups of variables in a model . . . . The concepts refer to a model-a system of equations-and not to the 'real' world the model purports to describe.

Learning is any change in a system that produces a more or less permanent change in its capacity for adapting to its environment.

By 1985, machines will be capable of doing any work Man can do.

Solving a problem simply means representing it so as to make the solution transparent.

Maybe we ought to have a world in which things are divided between people kind of fairly.

Many individuals and organization units contribute to every large decision, and the very problem of centralization and decentralization is a problem of arranging the complex system into an effective scheme.

The engineer, and more generally the designer, is concerned with how things ought to be - how they ought to be in order to attain goals, and to function.