Foldable phones naturally support displaying two applications side by side on adjacent screens. However, one-handed interaction with this dual-screen configuration faces two challenges: first, users must change grip to reach each screen; second, menus displayed on each screen take valuable screen real estate and can be difficult to reach. To address this, we investigated how the hinge of foldable phones can enrich tactile interaction and provide access to hinge menus, unifying interaction across both screens. In a first experiment, we examined how users hold a foldable phone at different fold angles and identified the thumb-accessible screen areas, validating that a hinge-based grip enhances reachability. In two subsequent experiments, we evaluated the feasibility and performance of hinge gestures, defined as touch inputs (tap, tap-tap or swipe) executed fully or partially on the hinge. Building on these findings, we designed hinge menus that combine hinge gestures for menu activation and item selection. Our final experiment identifies different hinge menus that outperform linear menus on adjacent screens. Our findings provide practical guidelines that can immediately inform and improve interaction on current foldable phones.

Visual interfaces are important in human motion to capture it, to visualize it, and to facilitate motion-based interactive systems. This workshop aims at providing a platform for researchers, designers and users to discuss the challenges related to the design of visual interfaces for motion-based interaction, in terms of visualization (e.g. graphical user interface, multimodal feedback, evaluation) and processing (e.g., data collection, treatment, interpretation, recognition) of human movement (e.g., motor skills, amplitude of movements, limitations). We will share experiences, lessons learned and elaborate tools for developing all the possible applications going forward.

This paper presents Rolling-Menu, a technique for selecting toolbar items, based on the use of roll gestures with a multidimensional device, the Roly-Poly Mouse (RPM). Rolling-Menu reduces object-command transition, resulting in a better integration between command selection and direct manipulation of application objects. Selecting a toolbar item with Rolling-Menu requires rolling RPM in a predefined direction corresponding to the item. We propose a design space of Rolling-Menu that includes different roll mapping and validation modes. A first user's study, with a simple toolbar containing up to 14 items, establishes that the best version of Rolling-Menu takes, on average, up to 29% less time than the Mouse to select a toolbar item. Moreover accuracy of the selection with Rolling-Menu is above 90%. Both the validation mode and the mapping between roll direction and toolbar items influence the performance of Rolling-Menus. A second study compares the three best versions of Rolling-Menu with the Mouse to select an item in two types of multidimensional toolbars: a toolbar containing dropdown lists, and a grid toolbar. Results confirm the advantage of Rolling-Menu over a Mouse.

Numerous interaction devices are designed through device composition. However, there is no conceptual support for this process and designers are left out to explore the space of combinations in an ad-hoc manner. In this paper we propose a design space for device composition, DECO, which focuses on the physical aspects of the composition. This design space is built around two main axes, namely Physical arrangement, which describes how elements are physically combined, and Physical manipulation, which describes how users manipulate each element. We first classify existing devices using our design space and then compare four of them to illustrate their similarities and differences. Using DECO, we design a new compound device: RPM2. This device is based on the combination of a regular mouse with the Roly-Poly Mouse. We describe in detail the user-centered iterative design process that leads to the final prototype. Finally we propose a set of design guidelines to assist the use of DECO for device composition.

We present the design and evaluation of the Roly-Poly Mouse (RPM), a rolling input device that combines the advantages of the mouse (position displacement) and of 3D devices (roll and rotation) to unify 2D and 3D interaction. Our first study explores RPM gesture amplitude and stability for different upper shapes (Hemispherical, Convex) and hand postures. 8 roll directions can be performed precisely and their amplitude is larger on Hemispherical RPM. As minor rolls affect translation, we propose a roll correction algorithm to support stable 2D pointing with RPM. We propose the use of compound gestures for 3D pointing and docking, and evaluate them against a commercial 3D device, the SpaceMouse. Our studies reveal that RPM performs 31% faster than the SpaceMouse for 3D pointing and equivalently for 3D rotation. Finally, we present a proof-of-concept integrated RPM prototype along with discussion on the various technical challenges to overcome to build a final integrated version of RPM.

This paper presents the KeyGlass system: a text entry system with dynamic addition of characters based on the previously entered ones. This system is optimized by the use of a prediction algorithm based on a lexicographic tree and bigrams.