[hackuser]

Regarding the webpage: That's an interesting perspective. I'm sure it's been considered before, but could the difference between the physical and digital interfaces result from complexity and not whether they are digital or physical?

I'm trying think of a complex physical interface - not one where the abstractions are buttons rather than a touch screen, but one without abstractions (if I understand your meaning on the webpage). Most man-made physical interfaces are simple, probaly for good reasons. A large sailing vessel, operated manually, is the best example I can think of, with the many sails, ropes, the rudder, etc. On one hand, my impression is that it's easier to conceive of them when using their physical interface; on the other I think an abstract UI could hide a lot of the complexity; for example it could present only the part of the interface I need for a particular task, hiding other parts and underlying mechanisms; also it could show helpful things that would be hidden in a physical interface, such as somthing blocked from view or info such as the stress on a mast or wind speed.

But I'm just thinking about it now; I assume someone has researched and thought about this issue ...