CONCEPT
Design as Hypothesis
Petroski's reframing of every engineered structure as a prediction about the future rather than a solution to the present — a hypothesis that the standing structure has not yet refuted but that every condition it encounters continues to test.
The engineer who believes she has produced a solution is inclined to defend it. The engineer who knows she has produced a hypothesis is inclined to test it — to look for the conditions under which it might fail, because finding those conditions before the world does is the difference between a controlled experiment and a catastrophe. Petroski developed this view most explicitly in Design Paradigms (1994), arguing that the standing bridge is not proof the engineer's model is correct but only proof that the model has not yet encountered the conditions that would reveal its error. Every day the bridge stands, the hypothesis has not been refuted. The non-refutation is not equivalent to validation. The distinction produces fundamentally different engineering practices: one oriented toward defending completed designs, the other oriented toward continuously testing them for the conditions that would expose the limits of the model they embody.
