Hand Occlusion on a Multi-Touch Tabletop

International audienceWe examine the shape of hand and forearm occlusion on a multi-touch table for different touch contact types and tasks. Individuals have characteristic occlusion shapes, but with commonalities across tasks, postures, and handedness. Based on this, we create templates for designers to justify occlusion-related decisions and we propose geometric models capturing the shape of occlusion. A model using diffused illumination captures performed well when augmented with a forearm rectangle, as did a modified circle and rectangle model with ellipse "fingers" suitable when only X-Y contact positions are available. Finally, we describe the corpus of detailed multi-touch input data we generated which is available to the community

Poking fun at the surface: exploring touch-point overloading on the multi-touch tabletop with child users

In this paper a collaborative game for children is used to explore touch-point overloading on a multi-touch tabletop. Understanding the occurrence of new interactional limitations, such as the situation of touch-point overloading in a multi-touch interface, is highly relevant for interaction designers working with emerging technologies. The game was designed for the Microsoft Surface 1.0 and during gameplay the number of simultaneous touch-points required gradually increases to beyond the physical capacity of the users. Studies were carried out involving a total of 42 children (from 2 different age groups) playing in groups of between 5-7 and all interactions were logged. From quantitative analysis of the interactions occurring during the game and observations made we explore the impact of overloading and identify other salient findings. This paper also highlights the need for empirical evaluation of the physical and cognitive limitations of interaction with emerging technologies

Integrating 2D Mouse Emulation with 3D Manipulation for Visualizations on a Multi-Touch Table

We present the Rizzo, a multi-touch virtual mouse that has been designed to provide the fine grained interaction for information visualization on a multi-touch table. Our solution enables touch interaction for existing mouse-based visualizations. Previously, this transition to a multi-touch environment was difficult because the mouse emulation of touch surfaces is often insufficient to provide full information visualization functionality. We present a unified design, combining many Rizzos that have been designed not only to provide mouse capabilities but also to act as zoomable lenses that make precise information access feasible. The Rizzos and the information visualizations all exist within a touch-enabled 3D window management system. Our approach permits touch interaction with both the 3D windowing environment as well as with the contents of the individual windows contained therein. We describe an implementation of our technique that augments the VisLink 3D visualization environment to demonstrate how to enable multi-touch capabilities on all visualizations written with the popular prefuse visualization toolkit.

Relative and Absolute Mappings for Rotating Remote 3D Objects on Multi-Touch Tabletops

The use of human fingers as an object selection and manipulation tool has raised significant challenges when interacting with direct-touch tabletop displays. This is particularly an issue when manipulating remote objects in 3D environments as finger presses can obscure objects at a distance that are rendered very small. Techniques to support remote manipulation either provide absolute mappings between finger presses and object transformation or rely on tools that support relative mappings t o selected objects. This paper explores techniques to manipulate remote 3D objects on direct-touch tabletops using absolute and relative mapping modes. A user study was conducted to compare absolute and relative mappings in support of a rotation task. Overall results did not show a statistically significant difference between these two mapping modes on both task completion time and the number of touches. However, the absolute mapping mode was found to be less efficient than the relative mapping mode when rotating a small object. Also participants preferred relative mapping for small objects. Four mapping techniques were then compared for perceived ease of use and learnability. Touchpad, voodoo doll and telescope techniques were found to be comparable for manipulating remote objects in a 3D scene. A flying camera technique was considered too complex and required increased effort by participants. Participants preferred an absolute mapping technique augmented to support small object manipulation, e.g. the voodoo doll technique

Adapting Multi-touch Systems to Capitalise on Different Display Shapes

The use of multi-touch interaction has become more widespread. With this increase of use, the change in input technique has prompted developers to reconsider other elements of typical computer design such as the shape of the display. There is an emerging need for software to be capable of functioning correctly with different display shapes. This research asked: ‘What must be considered when designing multi-touch software for use on different shaped displays?’ The results of two structured literature surveys highlighted the lack of support for multi-touch software to utilise more than one display shape. From a prototype system, observations on the issues of using different display shapes were made. An evaluation framework to judge potential solutions to these issues in multi-touch software was produced and employed. Solutions highlighted as being suitable were implemented into existing multi-touch software. A structured evaluation was then used to determine the success of the design and implementation of the solutions. The hypothesis of the evaluation stated that the implemented solutions would allow the applications to be used with a range of different display shapes in such a way that did not leave visual content items unfit for purpose. The majority of the results conformed to this hypothesis despite minor deviations from the designs of solutions being discovered in the implementation. This work highlights how developers, when producing multi-touch software intended for more than one display shape, must consider the issue of visual content items being occluded. Developers must produce, or identify, solutions to resolve this issue which conform to the criteria outlined in this research. This research shows that it is possible for multi-touch software to be made display shape independent

Light on horizontal interactive surfaces: Input space for tabletop computing

In the last 25 years we have witnessed the rise and growth of interactive tabletop research, both in academic and in industrial settings. The rising demand for the digital support of human activities motivated the need to bring computational power to table surfaces. In this article, we review the state of the art of tabletop computing, highlighting core aspects that frame the input space of interactive tabletops: (a) developments in hardware technologies that have caused the proliferation of interactive horizontal surfaces and (b) issues related to new classes of interaction modalities (multitouch, tangible, and touchless). A classification is presented that aims to give a detailed view of the current development of this research area and define opportunities and challenges for novel touch- and gesture-based interactions between the human and the surrounding computational environment. © 2014 ACM.This work has been funded by Integra (Amper Sistemas and CDTI, Spanish Ministry of Science and Innovation) and TIPEx (TIN2010-19859-C03-01) projects and Programa de Becas y Ayudas para la Realización de Estudios Oficiales de Máster y Doctorado en la Universidad Carlos III de Madrid, 2010

Gesture Typing on Virtual Tabletop: Effect of Input Dimensions on Performance

The association of tabletop interaction with gesture typing presents interaction potential for situationally or physically impaired users. In this work, we use depth cameras to create touch surfaces on regular tabletops. We describe our prototype system and report on a supervised learning approach to fingertips touch classification. We follow with a gesture typing study that compares our system with a control tablet scenario and explore the influence of input size and aspect ratio of the virtual surface on the text input performance. We show that novice users perform with the same error rate at half the input rate with our system as compared to the control condition, that an input size between A5 and A4 present the best tradeoff between performance and user preference and that users' indirect tracking ability seems to be the overall performance limiting factor

The effects of tool container location on user performance in graphical user interfaces

A common way of organizing Windows, Icons, Menus, and Pointers (WIMP) interfaces is to group tools into tool containers, providing one visual representation. Common tool containers include toolbars and menus, as well as more complex tool containers, like Microsoft Office’s Ribbon, Toolglasses, and marking menus. The location of tool containers has been studied extensively in the past using Fitts’s Law, which governs selection time; however, selection time is only one aspect of user performance. In this thesis, I show that tool container location affects other aspects of user performance, specifically attention and awareness. The problem investigated in this thesis is that designers lack an understanding of the effects of tool container location on two important user performance factors: attention and group awareness. My solution is to provide an initial understanding of the effects of tool container location on these factors. In solving this problem, I developed a taxonomy of tool container location, and carried out two research studies. The two research studies investigated tool container location in two contexts: single-user performance with desktop interfaces, and group performance in tabletop interfaces. Through the two studies, I was able to show that tool container location does affect attention and group awareness, and to provide new recommendations for interface designers