These days, it turns out that my son likes to watch tons of YouTube® videos of fire trucks, ambulances and first responders—oh yeah and dump trucks on my wife’s Kindle Fire®. Just peeking at him as I did on the way upstairs just hits home how important the the non-verbal is in user-interface. Knowing where to push, when to push and volume settings, etc. are learned and then understood. And that “pushing” and feedback loop is almost without limit!
And by the way, we have different user modes in computers, browsers, etc. I still don’t understand how that doesn’t exist on an iPad®. My son, like many users with little reservation, learn through just pushing buttons. This might mean they see a video or it might also mean they call 9-1-1. It would stand to reason that use of an iPad® delegated to a lesser experienced user should not have to result in settings changes or deletion of programs.