Usability Thoughts To Go…
Shown below is the front of a coffee dispenser I saw on a recent trip (with the critical part enlarged).
The label manually attached to the device tells users to “please pay attention to the displayâ€Â. As it seems, it was not enough simply having the display there, which provides instructions on which steps to take. Some of these steps are essential in respect to the goal of getting the desired beverage (e.g., when the user is asked to decide whether extra sugar shall be added).
Even though the display is illuminated, people seemingly did not pay proper attention to it, which resulted in interaction problems.
Areas Competing for Users’ Attention
This may be in part due to the fact that it is hard for a small display to “compete†for users’ attention with a large area (with all the buttons) in which they perform the interaction. Put in other words: users provide their input in an area different from the one where the system provides (a lot of) it’s output and very far away from the place where the final output (beverage) is provided.
Users’ Top-To-Bottom Taskflow Model
Users may even approach the machine with a top-to-bottom taskflow model in mind:
- Top: Read display first
- Middle: Push button(s)
- Bottom: Get cup with beverage
The fact that a look at the display in-between contradicts this strict top-to-bottom flow may also contribute to the necessity of putting a label on the device to remind users of the importance of the display.
A Potential Improvement
It would be interesting to see how users interact with the same device if the display was not constantly illuminated but only when a new message is shown, long enough to read it (a problem of its own) and the fade to dark or less illuminated. Light changes tend to provoke automatic “orientation reactions†and maybe this could be a way to improve interaction without having to attach additional labels on the device. Increasing the size of the display would not hurt, either.
Or one completely overhauls the device and equips it with a touchscreen, where users provide their input in the same place in which the system provides its messages. But the interaction concept for such an “iCoffee” would go beyond the brief thoughts I tried to sketch here…


























