Clocks, Bars and Balls

Children that rely on the use of single switches to access electronic devices, due to physical impairments, can play dynamic video games as their normally developing peers thanks to GNomon: one of the first framework for creating dynamic one-switch video games. However, children with physical impairments that also have cognitive disabilities find additional difficulties in using the current GNomon-based interface. To compensate these difficulties, the "classical" GNomon widget must be rethought and simplified. This paper proposes a parallel between three different widgets specifically designed for GNomon-based interfaces. Each widget employs metaphor in a different way and it has been evaluated with six children with motor and cognitive disabilities. The results are encouraging: a widget, based on the "big and small" concept, is preferred by children and is a candidate to make single-switch games easier to approach.