The (false) belief that large, innovative software designs can

be completely specified in advance and then painlessly

magicked out of the void by the normal efforts of a team of

normally talented programmers. In fact, experience has shown

repeatedly that good designs arise only from evolutionary,

exploratory interaction between one (or at most a small

handful of) exceptionally able designer(s) and an active user

population - and that the first try at a big new idea is

always wrong. Unfortunately, because these truths don't fit

the planning models beloved of management, they are

generally ignored.