This is an excellent article. The notion of "mode" is explicitly mentioned by Jef Raskin in his book "The Humane Interface" while discussing radio-controlled m

This is an excellent article. The notion of "mode" is explicitly mentioned by Jef Raskin in his book "The Humane Interface" while discussing radio-controlled model aircraft. It is sobering to see it mentioned here as "mode confusion", in the context of a commercial aircraft which led (directly or indirectly) to the death of 228 people.