Design of power buttons

Don Norman’s Design as Practiced describes some of the process and problems around redesigning the way Macs are turned on and off. (Via BeatnikPad)

It always fascinates me to see a description of all the forces that end up affecting a seemingly relatively simple thing as standardizing how a machine should be turned on and off. It’s also interesting see how international standards bodies can force consumer-confusing design by having particular meanings for icons that only people familar with the standard know about:

The symbol used earlier (a vertical line inside a circle) was not permitted because the European standards authorities insisted that the symbol was reserved for hard power switches. The triangle has no meaning, so it didn’t violate any standards. Few—European or American—are confident about the meaning of the vertical bar and circle (on and off, respectively), let alone a bar inside of circle (a toggled on/off), or vertical bar inside a broken circle (toggled soft-power), but the European standards committee is very strict. There are safety risks associated with thinking a shutdown switch removes all power from the machine when it doesn’t.)

So they can’t use the symbol many people now associate with “power on/of” because, according to some standards bodies, that symbol has a very specific meaning. It’s not safe to use even the “soft-power” symbol because not everyone knows the difference between the various standardized symbols (hard, soft power off). Ack.