A gradual refinement The steel rail is an artifact whose form has been carefully optimized. This gradual refinement of the design was done not by a single brilliant engineer but by more than a century of industrial evolution. The rail was never meant to be an object of beauty, but its cross section has all the elegance of fine typography. Brian Hayes, Infrastructure: A Guide to the Industrial Landscape elegancetypographytransportationevolutionchange
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 Frederick P. Brooks, Jr., What's Wrong With This Model? Changing constraintsDeciding what to designThe situation talks back