A diversity within its unity The vital power of an imaginative work demands a diversity within its unity; and the stronger the diversity, the more massive the unity. Dorothy Sayers, The Mind of the Maker diversity
The heat death of design Losing the design diversity means falling into a singular narrative of how design must be done, which grants unfair and self-reinforcing advantage to the mainstream while discouraging, stifling, or even punishing the idiosyncratic designers who bring unorthodox but remarkably innovative processes to the table. The true opportunity cost is the diverse future that humanity can no longer access. A future without diversity is fundamentally stagnant: imagine designs so standardized that you can’t tell them apart. While every design is guaranteed to be good, none will be great. New designs are marginally better than previous ones with the rate of improvement eventually approaching zero. We have reached the heat death of design. Chuánqí Sun, The vanishing designer diversity
Obsessed with absolute numbers Modernist planning was obsessed with absolute numbers, including the minimum dimensions of rooms, open space per capita, and the one-size-fits-all head counts of neighborhood units. This was often pegged at five to seven thousand and was used as a formula for determining the distribution of schools, shops, sports fields, and other facilities. The failure of such planning is not in its effort to be comprehensive or to equalize access to necessary facilities. It is, rather, the attempt to rationalize choice on the basis of a homogeneous set of subjects, a fixed grammar of opportunities, a remorseless segregation of uses, and a scientistic faith in technical analysis and organization that simply excludes diversity, eccentricity, nonconforming beauty, and choice. The utopian nightmare. Michael Sorkin, 20 Minutes in Manhattan Desired qualities of lightPredicted Mean Vote planningmetricsdiversity
The number of ways in which things work The importance of diversity is not so much the number of elements in a system; rather it is the number of functional connections between these elements. It is not the number of things, but the number of ways in which things work. Bill Mollison, Introduction to Permaculture diversityconnectionnetworkssystems
Exuberant diversity in a city's streets To generate exuberant diversity in a city’s streets and districts, four conditions are indispensable: The district, and indeed as many of its internal parts as possible, must serve more than one primary function; preferably more than two. These must insure the presence of people who go outdoors on different schedules and are in the place for different purposes, but who are able to use many facilities in common. Most blocks must be short; that is, streets and opportunities to turn corners must be frequent. The district must mingle buildings that vary in age and condition, including a good proportion of old ones so that they vary in the economic yield they must produce. This mingling must be fairly close-grained. There must be a sufficiently dense concentration of people, for whatever purposes they may be there. This includes dense concentration in the case of people who are there because of residence. Jane Jacobs, The Death and Life of Great American Cities diversitystreets
What's Wrong With This Model? A Chapter from The Design of Design by Frederick P. Brooks, Jr. What's wrong with the rational modelDeciding what to designEvaluating goodnessChanging constraintsThey just don't work that way+1 More
What's wrong with the rational model We Don’t Really Know the Goal When We Start We Usually Don’t Know the Decision Tree – We Discover It as We Go The Nodes Are Really Not Design Decisions, but Tentative Complete Designs The Goodness Function Cannot be Evaluated Incrementally The Desiderata and Their Weightings Keep Changing The Constraints Keep Changing Changing constraintsDeciding what to designThe situation talks back
Deciding what to design We Don’t Really Know the Goal When We Start The most serious model shortcoming is that the designer often has a vague, incompletely specified goal, or primary objective. In such cases, the hardest part of design is deciding what to design. I came to realize that the most useful service I was performing for my client was helping him decide what he really wanted. Today, we recognize that rapid prototyping is an essential tool for formulating precise requirements. Not only is the design process iterative; the design-goal-setting process is itself iterative. Knowing complete product requirements up front is a quite rare exception, not the norm. Therefore, goal iteration must be considered an inherent part of the design process. What's wrong with the rational model iteration
Evaluating goodness The Goodness Function Cannot be Evaluated Incrementally The Rational Model assumes that design involves a search of the decision tree, and that at every node, one can evaluate the goodness function of several downward branches. In fact, one cannot in general do this without exploring all the downward branches to all their leaves, which is possible in principle, but leads to a combinatorial explosion of alternatives in practice. What's wrong with the rational model
Changing constraints The Constraints Keep Changing The explicit listing of known constraints in the design program helps here. The designer can periodically scan the list, asking, “Can this constraint now be removed because the world has changed? Can it be entirely circumvented by working outside the design space?” What's wrong with the rational model constraints
They just don't work that way Perhaps the most devastating critique of the Rational Model, although perhaps the hardest to prove, is that most experienced designers just don’t work that way. “Conventional wisdom about problem-solving seems often to be contradicted by the behavior of expert designers. Empirical studies of design activity have frequently found ‘intuitive’ features of design ability to be the most effective and relevant to the intrinsic nature of design. Some aspects of design theory, however, have tried to develop counter-intuitive models and prescriptions for design behavior.” — Nigel Cross
We must outgrow it Why all this fuss about the process model? Does the model we and others use to think about our design process really affect our designing itself? I believe it does. I believe our inadequate model and following it slavishly lead to fat, cumbersome, over-features products and also to schedule, budget, and performance disasters. The Rational Model, in any of its forms, leads us to demand up-front statements of design requirements. It leads us to believe that such can be formulated. It leads us to make contracts with one another on the basis of enshrined ignorance. A more realistic process model would make design work more efficient, obviating many arguments with clients and much rework. The Waterfall Model is wrong and harmful; we must outgrow it.