Digital tabletop systems allow users to work on computational objects in a flexible and natural setting. Since users can easily move to different positions around a table, systems must allow people to orient artifacts to their current position. However, it is only recently that rotation and translation techniques have been specifically designed for tabletops, and existing techniques still do not feel as simple and efficient as their real-world counterparts. To address this problem, we studied the ways that people move and reorient sheets of paper on real-world tabletops. We found that in almost all cases, rotation and translation are carried out simultaneously, and that an open-palm hand position was the most common way to carry out the motion. Based on our observations, we designed a new set of reorientation techniques that more closely parallel real-world motions. The new techniques, collectively called TNT, use three-degree-of-freedom (3DOF) input to allow simultaneous rotation and translation. A user study showed that all three variants of TNT were faster than a recent technique called RNT; in addition, participants strongly preferred

Tabletops have been used to support a range of colocated activities, from games to image sorting. However, their limited display space and resolution can restrict the kinds of collaborative interactions that take place. Our research is concerned with how to extend the tabletop by integrating it with other spaces and artifacts in the physical world. The aim is to continue to support collaborative tasks that are well suited to the tabletop while enabling those that are less so to be carried out using physical representations and spaces. We describe a physical-digital space that we built for this purpose and then a study that compared how groups collaborate on a design task when using this versus solely the tabletop. The findings showed that extending the tabletop into a physical space enabled groups to collaborate more easily and flexibly. 1.

We present a set of interaction techniques for electronic musical performance using a tabletop tangible interface. Our system, the Audiopad, tracks the positions of objects on a tabletop surface and translates their motions into commands for a musical synthesizer. We developed and refi ned these interaction techniques through an iterative design process, in which new interaction techniques were periodically evaluated through performances and gallery installations. Based on our experience refi ning the design of this system, we conclude that tabletop interfaces intended for collaborative use should use interaction techniques designed to be legible to onlookers. We also conclude that these interfaces should allow users to spatially reconfi gure the objects in the interface in ways that are personally meaningful. Categories and Subject Descriptors H.5.2 [User Interfaces]: interaction styles, input devices and strategies J.5: [Arts and Humanities]: performing arts

Tangible user interfaces (TUIs) provide physical form to digital information and computation, facilitating the direct manipulation of bits. Our goal in TUI development is to empower collaboration, learning, and design by using digital technology and at the same time taking advantage of human abilities to grasp and manipulate physical objects and materials. This paper discusses a model of TUI, key properties, genres, applications, and summarizes the contributions made by the Tangible Media Group and other researchers since the publication of the first Tangible Bits

This paper extends our understanding of tangible user interfaces (TUIs) by considering the different ways in which physical and digital objects can be computationally coupled. It proposes a framework based around the degree of coherence between physical and digital objects. Links between physical and digital objects are described in terms of a set of underlying properties (transformation, sensing, configurability, lifetime, autonomy, cardinality and link source). We use our framework to classify a representative selection of existing TUI systems. This classification raises key implications for the field of tangible computing. In particular our focus on enriching physical-digital links highlights the need to consider the asymmetry of these links, issues surrounding their configuration and the need to represent their nature to developers and users.

If a mobile computer knows how it is positioned and oriented in relation to other mobile devices nearby, then it can provide enhanced support for multi-device and multi-user interactions. Existing systems that provide position information to mobile computers are reliant on externally deployed infrastructure, such as beacons or sensors in the environment. We introduce a novel system, Relate, which provides fine-grained relative position information to co-located devices on the basis of peer-to-peer sensing, thus overcoming dependence on any external infrastructure. The system is realized as hardware/software plug-in, using ultrasonic devices for peer-to-peer sensing, USB to interface with standard mobile devices, and data abstraction and inference to map sensor data to a spatial model that maintains both quantitative and qualitative relationships. We present a set of services and applications to demonstrate the utility of the system and report experimental results on system performance.

Abstract: This system paper reports on some of the advantages tangible interaction can bring to chemistry education. The paper describes how we realized a Tangible User Interface (TUI) called Augmented Chemistry (AC), gives details on basic and specialized interactive tools working in this system, and outlines the educational context. Using the basic tools, elements can be chosen from a booklet menu and composed into threedimensional (3D) molecular models. The system with its tools shows a way to design for seamless integration of the physical and digital realms. Multiple tools can be used concurrently, thereby calling for users ’ two-handed skills. To teach an aspect of molecular chemistry − the octet rule − we extended the system into an educational workbench drawing on haptic and aural augmentation. The system design required contributions from optics, mathematics, molecular chemistry, software engineering, and 3D programming. Future challenges of this project lie in further system development and educational usability.

We present System Blocks, a physical interface that makes it easier for children to model and explore dynamic systems. A set of computationally enhanced blocks, made of wood and electronics, System Blocks can assist K-6 educators to teach the complex concepts of system dynamics and causalities. Learning to understand dynamic systems is an essential step in understanding the world around us. However, learning it at university, high school or even middle school level might be too late. By this age children have already developed their own models of how the world works. In this paper we will show how a set of physical objects can be used as a modeling and simulation tool, merging hands-on tinkering with computer simulation. Using blocks that behave as stocks, flows, variables and constants, our hope is that System Blocks will enable children younger than sixth grade to model, simulate and analyze systems that are meaningful to them.

Table top games involve social interaction that is impossible in computer games, yet computer support can offer valuable features to game designers. By developing augmented table top games with video see-through augmented reality, we are exploring the possibilities of face to face computer supported games. We discuss the role of social interaction in both table top and computer gaming, introduce our augmented game AR Tankwar, and present the results from initial evaluations.

In this paper we present STARS, a platform for developing computer augmented board games that integrate mobile devices with an interactive table. The aim of STARS is to augment traditional board games with computing functionality, but without sacrificing the human-centered interaction dynamics of traditional tabletop games. STARS consists of a specialized hardware setup and an interaction framework that dynamically couples mobile and stationary input and output devices with the game table. Depending on a current device configuration, different input and output modalities are available which can either be explicitly utilized by the human players or determined by the STARS platform with regard to a set of mode-specific attributes, available interface services, and demands from a specific game logic.