In Aza’s recent blog, he was looking for examples of good, and bad, user interfaces.

Here is the bath/shower tap that I found in my hotel here in Tokyo yesterday morning. After quite some trial-and-error, I’ve figured out that with this one tap, you can:

  • shower
  • or bath
  • or both
  • while adjusting temperature for each *independently*!!
  • and with a safety red button (visible on top left) which you have to press before you can raise shower temperature above 40C to avoid accidental scalding. Note the lack of scald control on the bath tap, as its not needed.
  • and with a separate water on/off lever (visible on top right), once you get the shower water temperature just right, you can leave the temperature knobs set, and the shower temperature will automatically be perfect tomorrow morning! :-)

While it does do all of these things quite well, and I do now like it, it was more of an IQ test then I needed in a pre-caffeinated, jet lagged state, first thing yesterday morning.

Putting hot/cold taps by the shower head, and another set of hot/cold taps by the bath spout is (probably) more complex to install, but would have been more intuitive to use, imho. Also, as a nit: while the red “scald-prevention” safety button makes sense, the other two red dots are only for alignment; using the same color red for those confused me into thinking they were also for safety / hot water. Took some experiments to backtrack and figure out one was shower, one was bath, and the extra red dots were decoys. And yes, I got quite wet in the process! :-)

UPDATE: I just discovered that part of the tap pivots!?!?! Part of it sticks out so far that I bumped into it while showering. At first I was worried that I broke it, but after some playing discovered its hinged and is designed to swing fully back to the wall in either direction. Thats good, because it makes standing in the shower much easier now. Of course, I’ve no idea why the water-into-bath tap had to protrude that far in the first place; somehow a shorter, non-pivoting, taphead seems like it would have been easier. John 12mar2009