Ghosts in the interface: Meta-user interface visualizations as guides for multi-touch interaction

Multi-touch large display interfaces are becoming increasingly popular in public spaces. These spaces impose specific requirements on the accessibility of the user interfaces: most users are not familiar with the interface and expectations with regard to user experience are very high. Multi-touch interaction beyond the traditional move-rotate-scale interactions is often unknown to the public and can become exceedingly complex. We introduce TouchGhosts: visual guides that are embedded in the multi-touch user interface and that demonstrate the available interactions to the user. TouchGhosts are activated while using an interface, providing guidance on the fly and within the context-of-use. Our approach allows to define reconfigurable strategies to decide how or when a TouchGhost should be activated and which particular visualization will be presented to the user.