Peer Evaluation

I am evaluating Daniel Josefsson's interface for booking laundry machines.

User Evaluation

The student residence where I stay in uses exactly such a system as described by Daniel, where residents can book 2 washing machines, 1 tumble dryer and 1 drip dryer in 3-hour slots, therefore I asked a neighbour of mine to evaluate the interface. He is a 20-year-old Englishman who has been in Uppsala on exchange for 4 months.

His comments are as follows:

• On the calendar screen, it should perhaps show your existing bookings in a different colour.
• The interface is clearly laid out and aesthetically pleasing.

He had no problems using the interface to perform the tasks as laid out in Daniel's scenarios.

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Heuristic Evaluation

I have also evaluated the interface using the heuristic evaluation method. The ten principles below are rated on a scale of 1 to 5, with 1 being Very Bad and 5 being Very Good.

Visibility of system status - 3
There is no explicit display that lets the user know what stage of the task he is at. However since this is a simple interface for a simple task, with only 4 different screens, it will not affect the user much. This can be improved by adding a title bar to each screen, that gives an indication of what the screen is about.

Match between system and the real world - 4
Only the English interface is available for evaluation, and it is clear and easily understood, with no complicated words used. Information is also presented logically.

User control and freedom - 4
"Back" buttons are provided where necessary, which is good. There is no "undo" function, however a booking that is added or removed in error can be manually removed/added by the user.

Consistency and standards - 5
The interface is consistent in its use of colors, words and other cues.

Error prevention - 4
The interface itself is not prone to errors. There is no confirmation screen to confirm the user's booking addition/removal, however, as mentioned above, it is rather easy for the user to manually "undo" any mistakes that he has made.

Recognition rather than recall - 4
This aspect can be improved by highlighting the user's own bookings in a different colour, in the screen where time slots are displayed for selection. It will be helpful to the user who deliberately spaces out his laundry bookings, for example once every 3 days. It is also helpful to users who want to book 2 consecutive time slots.

Flexibility and efficiency of use - 5
The simplicity of the task means that little can be done to make it more efficient.

Aesthetic and minimalist design - 5
The design is simple and easy to use, and pleasing to the eye.

Help users recognize, diagnose, and recover from errors - 3
No documentation is provided regarding error handling.

Help and documentation - 5
There is a prominent help button on the top-right corner of every screen, which is good. Concise instructions are also provided beside most buttons. No mention of separate help or documentation is made but it does not seem necessary for such a simple task and such a simple-to-use interface.