Most of what we do to get people ready to act in situations of encounter consists of drilling these lists into them sufficiently deeply so that they will be evoked quickly at the time of the decision.

Assuming that a tax increase is necessary, it is clearly preferable to impose the additional cost on land by increasing the land tax, rather than to increase the wage tax - the two alternatives open to the City (of Pittsburgh). It is the use and occupancy of property that creates the need for the municipal services that appear as the largest item in the budget - fire and police protection, waste removal, and public works. The average increase in tax bills of city residents will be about twice as great with wage tax increase than with a land tax increase.

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.

The situation has provided a cue; this cue has given the expert access to information stored in memory, and the information provides the answer. Intuition is nothing more and nothing less than recognition.

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

Enlightenments, like accidents, happen only to prepared minds.

The proper study of mankind is the science of design.