Towards hybrid interface specification for virtual environments

Many new multi-modal interaction techniques have been proposed for interaction in a virtual world. Often these techniques are of a hybrid nature combining continuous interaction, such as gestures and moving video, with discrete interaction, such as pushing buttons to select items. Unfortunately the description of the behavioural aspects of these interaction techniques found in the literature is informal and incomplete. This can make it hard to compare and evaluate their usability. This paper investigates the use of HyNet to give concise and precise specifications of hybrid interaction techniques. HyNet is an extension of high-level Petri Nets developed for specification and verification of hybrid systems, i.e. mathematical models including both continuous and discrete elements.