Which half? One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, "Do you have any controls?" Well the great surgeon drew himself up to his full height, hit the desk, and said, "Do you mean did I not operate on half of the patients?" The hall grew very quiet then. The voice at the back of the room hesitantly replied, "Yes, that's what I had in mind." Then the visitor's fist really came down as he thundered, "Of course not. That would have doomed half of them to their death!" God, it was quiet then, and one could scarcely hear the small voice ask, "Which half?" E.E. Peacock Jr., Seeing With Fresh Eyes science
Their wrongness is somehow more immediate In general, a successful design, which Alexander terms a good fit between form and context, can be declared only when we can detect no more [points that conform to the standard against which we judge]. It is "departures from the norm which stand out in our minds, rather than the norm itself. Their wrongness is somehow more immediate than the rightness." Henry Petroski, The Evolution of Useful Things Notes on the Synthesis of Form