Five

THE SCIENCE OF DESIGN

Creating the Artificial

THE LOGIC OF DESIGN: FIXED ALTERNATIVES

• Paradoxes of Imperative Logic
• Reduction of Declarative Logic
• Computing the Optimum
• Finding Satisfactory Actions

THE LOGIC OF DESIGN: FINDING ALTERNATIVES

Means-Ends Analysis

p 141

The condition of any goal-seeking system is that it is connected to the outside environment through two kinds of channels: the afferent, or sensory, channels through which it receives information about the environment and the efferent, or motor, channels through which it acts on the environment. [afferent and efferent information].

The computer problem-solving program called GPS [...] exhibits [...] how goal-directed action depends on building [a] bridge between the afferent and efferent worlds. On the afferent [...] side, GPS must be able to represent desired situations [...] as well as the present situation. It must be able also to represent differences between the desired and the present. On the efferent side, GPS must be able to represent actions [...]. To behave purposefully, GPS must be able to select [...] those particular actions that are likely to remove the particular differences [...]. In the machinery of GPS, this selection is achieved through a table of connections.

The Logic of Search

DESIGN AS RESOURCE ALLOCATION

An Example from Highway Design

Schemes for Guiding Search

p 147-148

... search processes may be viewed [...] as processes for seeking a problem solution. But they can be viewed more generally as processes for gathering information about problem structure that will ultimately be valuable in discovering a problem solution.

[...] Here is an important direction for research in the theory of design.

THE SHAPE OF THE DESIGN: HIERARCHY

The Generator-Test Cycle

Process as a Determinant of Style

REPRESENTATION OF THE DESIGN

Problem Solving as Change in Representation

p 153

[Number scrabble and tic-tac-toe]

Spatial Representation

The Taxonomy of Representation

SUMMARY - TOPICS IN THE THEORY OF DESIGN

p 155

As we draw up our curriculum in design -in the science of the artificial- to take its place by the side of natural science [...], it includes at least the following topics:

• The evaluation of designs:
  1. Theory of evaluation [...]
  2. Computational methods:
     • Algorithms for choosing optimal alternatives [...]
     • Algorithms and heuristics for choosing satisfactory alternatives
  3. The formal logic of design [...]
• The search for alternatives
  1. Heuristic search [...]
  2. Allocation of resources for search
• Theory of structure and design organization [...]
• Representation of design problems

ROLE OF DESIGN IN THE LIFE OF THE MIND

p 157

Many of us are unhappy about the fragmentation of our society into two cultures. [...] If we regret that fragmentation, then we must look for a common core of knowledge [...] A common understanding of our relation to the inner and outer environments that define the space in which we live [...] can provide at least part of that significant core.

Music is one of the most ancient of the sciences of the artificial.