Since it’s mostly used by adults for a brief hand-washing, it doesn’t need a red “hot” knob and a blue “cold” knob. The only affordance is the stick coming out of the top, so you just wiggle that until water comes out of the faucet.
Doors are also generally well-suited for their purpose. A user simply has to unlatch them with a knob or a handle or a bar, and then either push or pull them. The only time we might need to be instructed in their use is if the door itself is malfunctioning. I recently saw such a door- the bar had some kind of problem and could only be pushed at the mid-point. If a user pushed it anywhere else, it would jam. There was an earnest homegrown attempt to instruct users through color and text.
I stood to one side and watched as three people in a row pushed on the red part of the bar and jammed the door. What’s the problem?
The main issue is the large text, “Press to Exit”. This is a bright signal, and it confirms our understanding of the operation of the bar-latch door design; push on the bar. Since most people don’t anticipate having an issue using a door, it’s likely that they scan the sign and simply do what they think they’re supposed to do; push the bar anywhere. They’re leaving a facility, so it’s a transitional time that is probably occupying their thoughts and there’s not much at all to spare for low-risk issues like potentially pushing the wrong part of the bar.
Since the bar is the affordance that we want them to focus on, I would have put a very simple message there. I’d also dump the red tape- colorblind visitors won’t benefit from it, and it’s just noise to those with normal vision. Here’s what I would have done.
The green tape is just bright enough to co-opt attention, and the message is simple and located exactly where the action needs to take place.
Design improvements like this are not earth-shaking, especially given the low risk associated with failing to follow the instructions. However, identifying error-prone conditions and addressing them regardless of risk is crucial for building trust in any interface.
