FAUCET USABILITY V1.0
For a first blog post let's start with something from my own experience.
Some months ago I changed my place in Aachen and during the first day I was dazzled by the douche faucet in the bathroom. I thought: What an evil designer mind would create such a thing? Before proceeding with my insights, I want to explain to you how it works.
Here it is. It has two turning ends: one for temperature and another for controlling the water amount. They are not badly indicated according to me (could be better but I've seen much worse cases). I will not comment the 38 on the right side. My guess is that it's a neutral temperature in Centigrade related to the human body typical temperature, even though it's just a guess. However there is one drawback that I cannot explain to myself still even though I have an theory but it's far from being even plausible. Looking closer to both turning sides one sees the following picture:
So turning forward or upward means more water (not a bad mapping), however temperature is turned the other way around. Turning forward or upward means lower temperature of the water. There might be a good reason for this inconsistency but in terms of usability it is an epic failure.
On a sidenote the button-like things are probably some kind of an economy measure. The one for the water amount limits rotation to some point and if you want even more water you need to press it to twist further. However I have not figured out what the one on the temperature handle does (some months later I figured out that it limits the temperature level similarly to the one for amont of water but since I prefer colder showers I never need to bother with it)
So my conclusion is that designer did an interesting job introducing some elementary gulfs in the 7 stages of action model but on the other had he gave an opportunity for someone else to make this quite flawed design a perfect match.
I don't know who that was, but our John Doe is the guy who made the decision to order these faucets for the bulding. And why his choice was so ingenious? Because of context!!! Since only a single person uses the faucet for continuous amount of time before another one moves in. And during this long period he sets the temperature once and from then on he only needs to use the water amount handle. Much better than standard single-handle faucetsfor controlling temperature and amount at the same time (I always need a minute or two to get my preferred temperature) or even old turning faucets, where one is for hot water and another one for cold (it also takes quite some time and a bit more effort). The only time when this breaks through is when you have somebody over and he/she takes a shower and spoils your perfect adjustment.