How Not To Design Stuff: Dellusions Of Power


The University of Southern Maine employs the use of a large number of Dell Optiplex GX280 computers in labs and classrooms. They are modern computers, pretty fast, quiet, not real pretty, and the power button of these computers looks pretty much like any other typical power button on the planet: it’s round, it has that funky little circle-with-a-line-symbol-of-power-thingy, and it glows green. However, one unfortunate design flaw has caused lost time and headaches.

How, you ask, can the design of a power button result in confusion and lost work? Visual feedback.

Fact: The button glows green when the computer is on.
Fact: People expect something on the computer to glow green when the computer is on.
However: In order to tell that the button is glowing, one must look almost straight at it from the front. If you are a little to the side – which is the normal arrangement for the Labs – you can’t see the light.

Result: If the computer is positioned anywhere but in front of the user, the little green glow is invisible unless one leans over and peers at the button.

One would not think this to be a terrible problem, a dinky little light doesn’t make that much difference. After all, you can also tell if the computer is on by looking at the monitor.

That logic is conveniently defeated by two different circumstances.

1) Some classroom computers are attached solely to a projector – if the projector isn’t on (or is blanked), there is no feedback from the screen.
2) In the John Mitchell Center CAD lab, all the monitors are on a separate power circuit and can be turned off at the professor’s whim.

We are back to using the power button glow as the sole indicator of computer status. This is a dangerous prospect to entertain if the glow cannot be easily seen – and did I mention that pushing the power button when the computer is on immediately shuts it down?

(Cue scary theme music.)

You push the button. Nothing seems to happen for a couple seconds. You push the power button again. The computer you just turned on shuts off again. You wait longer this time, and are confused. You push the power button again, firmly, and wait longer and something finally shows up on the screen. You can now do useful work before class starts.

Then, the monitors are shut off during lecture and you forget the computer is on – and there are no visible glowy lights to tell you either way. The lecture is over and you push the power button to start the machine up. It shuts off. And, since the computers have DeepFreeze (or equivalent) installed, anything that you saved to the internal drive is wiped clean at boot.

It sounds ridiculous, but I’ve seen people lose valuable work because of that. Extra frustration, problems, and lost work – all because the power button doesn’t provide a good (i.e., visible!) visual cue.

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