Chapter 5: Science of Design

Definition, p 130:

Everyone designs who devise courses of action aimed at changing existing situations into preferred ones. The intellectual activity that produces material artifacts is no different fundamentally from the one that prescribes remedies for a sick patient or the one that devises a new sales plan for a company or a social welfare policy for a state.

Examples: architects, doctors, managers, politicians, teachers, ....

generic design - does it exist?

design as an activity has a distinct conceptual and cognitive realization from nondesign activities

it can be abstracted away from the particulars of the knowledge base of a specific task or discipline and studied in its own right

Design Deals with Wicked or Ill-Defined Problems

Rittel in Cross "Developments in Design Methodology"

Design deals with Wicked or Ill-Defined Problems

Thoughts on Design

A Piece of Wisdom: "The best is often the enemy of the good"

going from Los Angeles to Boston

subjective computability versus objective computability

Informational and Computational Efficiency

two representations are informationally equivalent if all of the information in the one is also inferable from the other, and vice versa. Each could be constructed from the information in the other.

two representations are computationally equivalent if they are informationally equivalent and, in addition, any inference that can be drawn easily and quickly from the information given explicitly in the one can also be drawn easily and quickly from the information given explicitly in the other, and vice versa

Representation of the Design

Number Scrabble <------> Tic Tac Toe

the multilated chess board <------> the Match-Making story

Roman Numerals <------> Arabic Numerals

Solving a problem simply means

representing it so as to make the solution transparent

---> we need a taxonomy of representations

The Shape of the Design: Hierarchy


The Problem of Modularity

To design a complex structure, one powerful technique is to discover viable ways of decomposing it into semi-independent components corresponding to its many functional parts. The design of each component can then be carried out with some degree of independence of the design of others, since each will affect the others largely through its function and independently of the details of the mechanisms that accomplish the function.

Topics in the Theory of Design

Three Generations of Design Methods
from the History of Architectural Design

1st Generation (before 1970):

directionality and causality

separation of analysis from synthesis

major drawback: perceived by the designers as being unnatural; does not correspond to actual design practice

2nd Generation (in the early 70's):

participation -- expertise in design is distributed among all participants

argumentation -- various positions on each issue

major drawback: insisting on total participation, neglecting expertise possessed by a well-informed and skilled designer

3rd Generation (in the late 70's):

inspired by Popper: the role of the designer is to make expert design conjectures

these conjectures must be open to refutation and rejection by the people for whom they are made (---> end-user modifiability)

Integrating Problem Framing and Problem Solving

Simon:

In oil painting every new spot of pigment laid on the canvas creates some kind of pattern that provides a continuing source of new ideas to the painter. The painting process is a process of cyclical interaction between the painter and canvas in which current goals lead to new applications of paint, while the gradually changing pattern suggests new goals.

Computer Science Technology Board:

system requirements are not so much analytically specified as they are collaboratively evolved through an iterative process of consultation between end-users and software developers

Rittel:

one cannot understand a problem without having a concept of the solution in mind

one cannot gather information meaningfully unless one has understood the problem but one cannot understand the problem without information about it

L3D Research to Integrate
Problem Framing and Problem Solving

Design in Software Engineering

Rigor versus Relevance

Donald Schön "The Reflective Practitioner":

In the geography of professional practice, there is a very dry, high ground where you can practice the techniques and use the theories on which you got your PhD. Down below there is a swamp where the real problems live. The difficulty to decide whether to stay on the high ground, where you can be rigorous but deal with problems of lesser importance, or go down into the swamp to work on problems you really care about in a way you see as hopelessly unrigorous. It is the dilemma of rigor or relevance. You can't have both, and the way in which people choose between them sets the course of their professional lives.

One consequence is that researchers who stick to the high ground become not only separate from practice but increasingly divergent from it. As a result, engineering scientist have very little so say to engineering designers; cognitive psychologists very little to say to teachers.

The position of the professionals who stay on the high ground is difficult, because they must find ways to cut off pieces of problems that don't fit their models.

Problems with the 1st Generation

motivation:

The experience of having participated in a problem makes a difference to those who are affected by the solution. People are more likely to like a solution if they have been involved in its generation; even though it might not make sense otherwise.

asymmetry of ignorance ---> professional expertise dominated

deprofessionalization ---> redefining the role of high-tech scribes