Master's thesis by Writser Cleveringa
In recent years, a new type of human-computer interaction has surfaced: gestural interaction. A computer with a gestural interface tries to interpret human gestures via mathematical algorithms. Gestural interfaces appear in many forms, ranging from a computer that tries to recognize human emotions using a video camera to a gaming console that uses special input devices to detect hand motion.
Gestural interaction is also possible on touch screens. Users can interact with a computer by drawing gestures on a touch screen, usually with their fingers or with a stylus. The research in this thesis focuses on improving gestural interaction on touch screens by rendering previews of possible gestures on the screen when users try to draw a gesture. We named this concept gesture previewing.
This thesis gives an overview of our research. Interfaces for touch screens are discussed, in particular the advantages and disadvantages of gestural interfaces. To offset the disadvantages of gestural interaction on touch screens we introduce the concept of gesture previewing: giving users visual feedback about what gestures they can draw and presenting this feedback in such a manner that it does hinder expert users. We also introduce the concept of ‘composed gestures’: grouping gestures in such a way that a touch screen can give more efficient feedback to users.
At TNO, Groningen we have developed a proof-of-concept framework for integrating gesture previews in existing applications. The implementation of this framework and its integration in an existing application is discussed. A user study was also conducted to find out if gesture previews are actually useful and if users like working with them. This user study yielded some interesting results and these are also presented. Finally we draw conclusions regarding the usability of gesture previews and suggest areas of interest for future research.