Nokia 770 :: Some UI guidelines for N770 developers

Thursday June 16th 2005, 23:15 Category: Nokia 770 development

J. Manrique Lopez de la Fuente posted some advice for GUI developers in maemo-developers regarding the perceived slowness of Nokia 770.

Wherever possible, use multi-threading to push latency into the background.
Latency can often be hidden from users through multi-tasking techniques, letting them continue with their work while transmission and computation take place in the background.
Reduce the user’s experience of latency.
Acknowledge all button clicks by visual or aural feedback within 50 milliseconds.
Display an hourglass for any action that will take from 1/2 to 2 seconds.
Animate the hourglass so they know the system hasn’t died.
Display a message indicating the potential length of the wait for any action that will take longer than 2 seconds.
Communicate the actual length through an animated progress indicator.
Offer engaging text messages to users informed and entertained while they are waiting for long processes, such as server saves, to be completed.
Make the client system beep and give a large visual indication upon return from lengthy (>10 seconds) processes, so that users know when to return to using the system.
Trap multiple clicks of the same button or object. Because the Internet is slow, people tend to press the same button repeatedly, causing things to be even slower.