How not to design a water dispenser
Tuesday, December 21, 2010 12:16 am
The water dispenser at work has two functions:
- Dispense cold water
- Dispense hot water
Yet it has three buttons!
So now I have to first select the water temperature (cold is default) and then press another button to dispense the water. Notice, there’s also a light for an indicator of your current selection (green is cold, red is hot).
I thought this was always silly; it’s just unnecessarily complicated. There’s a very simple precedent for this: one blue button (for cold) and one red button (for hot).
And then I saw this next design, which by comparison makes the previous design seem downright brilliant.
This is a combined water and ice dispenser. Look at those buttons in the top right. In the picture they look ok, but when faced with this machine in real life, no one sees those buttons; they just too far away from what the user is looking at.
Now, by using those on and off switches at the top right, you can pick whether it will dispense (1) water, (2) ice, (3) both, or (4) neither.
The buttons at the top right give you the ability to have 4 states, but 2 of them are useless. First, why would a user ever have it in “neither” mode (with both buttons off)? And second, while the “both” mode seems reasonble (“yes, I’d like ice water”), in practice it’s useless. When you try to dispense both, the ice drops into the water, which splashes everywhere and makes a mess.
Again, there’s a simple precedent for this: most refrigerators can dispense 3 things (ice, crushed ice, or water) with just one selection button or slider.




