We present an interaction technique combining tactile actions and Midair pointing to access out-of-reach content on large displays without the need to walk across the display. Users can start through a Touch gesture on the display surface and finish Midair by pointing to push content away or inversely to retrieve a content. The technique takes advantage of wellknown semantics of pointing in human-to-human interaction. These, coupled with the semantics of proximal relations and deictic proxemics make the proposed technique very powerful as it leverages on well-understood human-human interaction modalities. Experimental results show this technique to outperform direct tactile interaction on dragging tasks. From our experience we derive four guidelines for interaction with large-scale displays.

In mobile touchscreebn interaction, an important challenge is to find solutions to balance the size of individual widgets against the number of widgets needed during interaction. In this work, to address display space limitations, we explore the design of invisible off-screen toolbars (ether-toolbars) that leverage computer vision to expand application features by placing widgets adjacent to the display screen. We show how simple computer vision algorithms can be combined with a natural human ability to estimate physical placing to support highly accurate targeting. Our ether-toolbar design promises targeting accuracy approximating on-screen widget accuracy while significantly expanding the interaction space of mobile devices. Through two experiments, we examine off-screen content placement metaphors and off-screen precision of participants accessing these toolbars. From the data of the second experiment, we provide a basic model that reflects how users perceive mobile surroundings for ether-widgets and validate it. We also demonstrate a prototype system consisting of an inexpensive 3D printed mount for a mirror that supports ethertoolbar implementations. Finally, we discuss the implications of our work and potential design extensions that can increase the usability and the utility of ether-toolbars.