good & bad usablitythe tap example

Everyone interested in HCI and Usability saw the cover picture of The Design of Everyday Things by Donald Norman. But there are examples about good and bad usability all around us, every day and I want to share one of mine.

I realized how much more comfortable the shower tap at my parents place is, compared to the one in my shared flat.

don't move! If you are lucky, the water gets only turned of... otherwise you get frozen or boiled...
Don't move! If you touch it and you are lucky, the water gets only turned off... otherwise you get frozen or boiled.
an good example of a water-tap for a shower
A good example of a water-tap for a shower.

The example to the left  is a typical one – most probably following an assumption like “this tap is working for the washbowl, so it will do for a shower as well”. As it is mounted waist-high, it is easy to reach, also by mistake, which can be quite dangerous as it can easily be turned towards hot water by a slight touch. The re-engineered example on the right shows a functional and easy-to-use solution, in addition, the water temperature can be set up very precisely, but most important, there is no way to change the water temperature by accident as it is selected with a knob. Additionally, due to the knob, its almost impossible to reach the handle, which is used to set up the water amount, by accident.