Stick like hell When the Wizard of Menlo Park called invention 10 percent inspiration and 90 percent perspiration, he was speaking not only about the creative act of inventing but also about the whole inventive process needed to bring more than intellectual success. Edison warned against discouragement during the perspiration phase in the following way, reminding us that we get things to work by the successive removal of bugs: Genius? Nothing! Sticking to it is the genius! Any other bright-minded fellow can accomplish just as much of he will stick like hell and remember nothing that's any good works by itself. You've got to make the damn thing work!...I failed my way to success. Thomas Edison, The Evolution of Useful Things inventionsuccess
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