When I moved into my latest apartment, I faced a familiar situation in the living room: Two identical, unlabelled switches, with one controlling the ceiling fan and another controlling the light. Now, it would have been easy enough simply to learn and remember which switch was which. So, too, would it have been easy simply to label one of them with the word "FAN", and have done with it. But my taste for rational design was offended by the confusing switches, so I decided to fix them properly. The entire problem put me in mind of a story from Donald A. Norman's book, The Design of Everyday Things.
When Dr. Norman moved into his custom-built home, he was confronted by the decidedly irrational vertical array of six unlabelled light switches, pictured above, to control the various lights in his (evidently rather large) living room. Such an array is terribly confusing, of course, and much time is wasted in experimentation until the ordering of the switches is learned, and even thereafter guests will probably always be at a loss.
Norman's solution, to shift the orientation of the panel from vertical to (approximately) horizontal, with the switches superimposed on a floorplan of the living room, is pictured above. It is a prime example of what he calls "natural mapping" in the layout of controls. The principle of natural mapping is straightforward: Controls should be chosen, laid out, and oriented in such a way that the function of each control is intuitive, minimizing labelling or eliminating it altogether. (For my own brief "case study" of natural layout in the mapping of automative door controls, click here.) If labelling is absolutely necessary, graphics are preferable to text because, among other things, graphics do not assume literacy in a particular language on the part of the user. Both these pictures are scanned from p. 97 of The Design of Everyday Things.
My own solution lacks the elegance of Norman's idea, but it also lacks the expense. His problem, like his living room, was much more extensive than my own. The process makes use of these fixtures...
...which are available at most hardware stores. They are intended for use with switches on papered walls, holding swatches of matching wallpaper so that the switch plates blend in. The acrylic cover has the added advantage of protecting the paper around the switch from picking up dirt and grime from grubby fingers. As I recall, the fixtures are available in double- and triple-gang configurations, as well.
Although the "on label" use of the acrylic switch plate is relatively mundane, it can be exploited to make any custom switch plate one might want. Any paper image that fits inside (7 x 12.2 cm) is usable, and the clear plastic cover prevents it from being damaged during daily use. Another solution, besides using icons like those presented here, might be to put a photograph of the appliance, as it appears in the room, controlled by each switch in the cover for that switch.