12 February 2010

one-button usability

My sister has a very well designed electronic kitchen scale which has only a single button to perform three functions:
  • switch it on and off
  • subtract container weight, that is, switch from gross to net weight
  • calibrate the scale
How does this magic work? The single button is labeled  “On Off Tara”. When the scale is off, pressing the button will switch it on and calibrate it to show a weight of 0. When it is on and showing 0, pressing the button will switch it off. In all other cases, pressing the button will recalibrate the scale to show 0, such that when adding more things to weigh, only the added weight will be shown.

This design is not just ingeniously simple, it is also quite robust with regard to the order of steps. For example, one can first put an empty container on the scale, then switch it on, and it will automatically start from 0 to measure what you actually want to weigh.

2 comments:

Sarah, ZH said...

Usability is always in the eye of the beholder. I have one of these scales and never quite figured how to switch them off. Thanks for explaining. ;)

Joel said...

an even simpler scale (no electronics and a tare function):
http://www.evasolo.com/products-kitchenscales.html

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