In this project the goal was to optimize the use flow and interaction with an microwave oven interface from an usability perspective. This was done through iterative cycles of usage evaluations, re-designing and prototyping.
The starting point – the Whirlpool MAX109 – is not an archetypical microwave oven: Its form factor is rather narrow and it features a rounded back. This means that the interface is placed on the strip underneath the door, not in its usual position on the side.
Usability issues and design goal
A first user test showed that there are many issues with the usability of the interface. Both the unconventional form factor and the amount of features make it difficult for users to quickly and conveniently navigate through the options.
In the following design process, the following four main issues were targeted:
- Non-logical clustering of features and modes
- Too many decisions to make
- Scroll-wheel movement doesn’t relate to interface
- Navigation area is spread out too widely
Redesign of the menu structure: Forming logical clusters
The information architecture of the menu was clustered into three main functions according to the cognitive understanding of microwave ovens:
- Type of food
- Cooking program
- Manual mode
In each of these functions, there are only one to a maximum of three decision to make, which makes whole cooking process much more convenient.
Redesign of the interface
Five different concepts were developed using wire-frames, paper prototypes and a fully interactive high-fidelity prototype.
The final iteration of the improvement features a central scroll-wheel, which is directly linked to the available options next to it. By pushing it, the selected option is confirmed. With this, the main interactions can be done in this scroll-wheel.
The final design is designed to
- The depth of menu structure and amount of decisions to make is reduced
- Logical and user-friendly clustering of features and functions
- The scroll wheel directly relates to the interface
- The interface area is compact and ergonomic
User testing the final design
In order to test the redesign, an interactive version was built and run on an iPad, which was attached in front of the original device.
We then tested three different scenarios by asking our participants to prepare different meals with the new interface.
Improvements in usability and desirability
The final design was evaluated against the original design using the AttrakDiff tool, with which the usability and attractiveness of interactive products can be compared.
The redesign (yellow circle) was perceived as much more practical than the original interface. At the same time, users also thought the new design was more desirable and pleasant to use.
“I like the combination of the interface with the physical buttons. It’s easy to figure out.”