In this paper we present the concept of Emergeables-mobile surfaces that can deform or 'morph' to provide fully-actuated, tangible controls. Our goal in this work is to provide the flexibility of graphical touchscreens, coupled with the affordance and tactile benefits offered by physical widgets. In contrast to previous research in the area of deformable displays, our work focuses on continuous controls (e.g., dials or sliders), and strives for fully-dynamic positioning, providing versatile widgets that can change shape and location depending on the user's needs. We describe the design and implementation of two prototype emergeables built to demonstrate the concept, and present an in-depth evaluation that compares both with a touchscreen alternative. The results show the strong potential of emergeables for on-demand, eyes-free control of continuous parameters, particularly when comparing the accuracy and usability of a high-resolution emergeable to a standard GUI approach. We conclude with a discussion of the level of resolution that is necessary for future emergeables, and suggest how high-resolution versions might be achieved.

2D or 3D gesture commands are still not routinely adopted, despite the technological advances for tracking gestures. The fact that gesture commands are not self-revealing is a bottleneck for this adoption. Guiding novice users is therefore crucial in order to reveal what commands are available and how to trigger them. However guiding systems are mainly designed in an ad hoc manner. Even if isolated design characteristics exist, they concentrate on a limited number of guidance aspects. We hence present a design space that unifies and completes these studies by providing a coherent set of issues for designing the behavior of a guiding system. We distinguish Feedback and Feedforward and consider four questions: When, What, How and Where. In order to leverage efficient use of our design space, we provide an online tool and illustrate with scenarios how practitioners can use it.

Abstract. Tangible sliders are successfully used as they do not need visual attention. However, users need to balance between opposite concerns: size and precision of the slider. We propose a resizable tangible slider to balance between these concerns. Users can resize the on-screen representation of the slider by resizing the tangible slider. Our aim is to benefit from both tangibility and flexible control, and balance between precision and minimum size. We measured the pointing performance of our prototype. We also assess the potential drawback (additional articulatory task for deformation) by evaluating the impact on precision of the additional articulatory task for deformation: for pursuing a target, we show that our resizable prototype supports better precision than its small counterpart as long as users do not need to resize it more often than around every 9 seconds.