The skill of perception The newborn baby and the [blind man suddenly gifted with sight] do not have to learn to see. Sight is given to them. But they do have to learn to perceive. Perception is learnt and learnt slowly. Skill is required for perception as for speech. We are largely unaware of the skill we exercise. None of the things we have to learn to perceive are self-evident, or, apparently, instinctively evident. No doubt, however, we have an instinctive aptitude for this learning, and once we have learnt we cannot easily see as though we had not. As Ruskin says, one has to strive, if one is to see with the 'Innocent Eye'. David Pye, The Nature and Aesthetics of Design The innocence of the eyethe innocent i seeingperceptionlearninginstinct
The ordering of steps The ordering of steps is based on the following concept: that as each step progresses and the design is further detailed, there is an iteration with the preceding and succeeding steps but rarely with the more remote steps in the sequence...what we have is an effective fallback position that tends to maximize the extent of early work that is salvageable and preserved. Winston W. Royce, Managing the Development of Large Software Systems The rational model of design