The relationship between controls and their actions follows the principles of good mapping, enhanced as much as possible through spatial layout and temporal contiguity. (Norman, 2013)
Figure 6: Standing fan
This is the standing fan in my bedroom. The interface for fan speed controller applied the fundamental design principle of mapping, where it arranges the position of button from low speed to high speed. It is a clear and simple indicator that show that which button is for which speed as we have the concept of low speed at bottom and high speed at top position. Moreover, the button also labelled with numbers to modify to idea of the position of button arrange based on the speed. In a nut shell, I have no problem with this interface design and it is easy to understand.
REFERENCE:
Norman, D. (2013). The design of everyday things: Revised and expanded edition. Constellation.
Design of Everyday Things by Donald Norman 