At work we have a very simple microwave with only 4 buttons (not counting the door open lever/button):
This microwave manages to be one of the most effective user interfaces I've ever come across. Pressing the plus ("+") button ups the time in 10 second increments, until you reach 90 seconds, and then it ups the time in 1 minute intervals. Once you pass 90 seconds, the display shows whole minutes. You can't set a time of 17 seconds, for example, or even 6 minutes and 30 seconds.
Pressing the minus button decreases the time by 1 minute if the current time is more more than 90 seconds, and then it decreases the time in 10 second intervals down to zero. Pressing the "Start" button increases the time in 1 minute intervals, but only up to 3 minutes.
All this I've figured out by experimentation. I reckon it's the lack of numeric precision and the associated traditional numeric keypad that makes this 4-button microwave so effective. The "+", "-", "Start" and "Cancel" buttons are self-explanatory, and experimenting with them instantly tells you what they do.
Contrast this with the horrible boiling water unit that I blogged about previously, where the buttons are unlabeled (and clicking them does nothing anyway), and the 4-button microwave comes out a long way in front.
Tags: design, kitchen, ui
posted @ Monday, September 01, 2008 1:13 PM