Human Factors and Ergonomics Society Europe Chapter
Bad Ergonomics - Example 16

Copy Machine
control brightness

So your first copy wasn't dark enough, and then... I'm sure you had to guess which button to press to obtain a darker copy (it probably cost you an extra copy).
Perhaps an alternative is to make use of the established symbol for volume control, i.e.
lightervolume control triangledarker

Submitted by Niels Taatgen

Next example
Previous example

Back to index of bad ergonomics