It’s the year 2070. You are a 20 year recruit that is going to travel back in time 12-monkey style to try and save the world. You get to 2025, you find proof on a iPhone and you need to take a screenshot and send to a safe email address. Do you have a change at discovering how to take a screenshot?
The other day I was locked out of my car. I had my keys, but the key fob button wouldn’t work and neither would the little button on the door handle that normally unlocks the car. At this point, every action I had to take in order to get into the car required knowledge of a hidden control. Why didn’t I just use my key to get in? First, you need to know there is a hidden key inside the fob. Second, because there doesn’t appear to be a keyhole on the car door, you also have to know that you need to disassemble a portion of the car door handle to expose the keyhole.
Philip Kortum has a nice article on how this quest towards “clean” interfaces actually hurts usability.