What’s the Waiter Doing With the Computer Screen? ⇥
Richard Gatarski, quoting a maître d’hôtel:
You can check off a reservation in the system, with the mouse, but hey, it’s at least four clicks away from this screen. And you can’t tell if the guests have been showed to their table or are waiting in the bar. So it’s much easier just to draw on the screen [with a whiteboard pen]. (And when the evening is over you just wipe the screen with a cloth.)
A real-world example of where it becomes clear nobody has actually tested the user interface.