Enabling comfortable thumb interaction in tablet computers: a Windows 8 case study

Holding a tablet computer in two hands and interacting via the thumbs is an important and commonly observed method of tablet interaction. This paper presents a methodology for measuring and reporting thumb reach in a way that enables designers of user interfaces (UI) to design UIs that can be comfortably reached by the thumbs. The process is to identify the relevant anthropometric measure and target population, identify how people grip the device, measure reach areas for different groups and grips, and to use the data to create graphical ‘heat maps’ along with guidance that designers can use to place their interface elements into easily reachable areas of the screen. The methodology is illustrated with an example of how it was used in the development of Microsoft Windows 8.