Researchers seeking alternatives to traditional desktop computers have begun exploring the potential collaborative benefits of digital tabletop displays. However, there are still many open issues related to the design of collaborative tabletop interfaces, such as whether these systems should automatically orient workspace items or enforce ownership of workspace content. Understanding the natural interaction practices that people use during tabletop collaboration with traditional media (e.g., pen and paper) can help to address these issues. Interfaces that are modeled on these practices will have the additional advantage of supporting the interaction skills people have developed over years of collaborating at traditional tables. To gain a deeper understanding of these interaction practices we conducted two observational studies of traditional tabletop collaboration in both

Evaluating distributed CSCW applications is a difficult endeavor. Frameworks and methodologies for structuring this type of evaluation have become a central concern for CSCW researchers. In this paper we describe the problems involved in evaluating remote collaborations, and we review some of the more prominent conceptual frameworks of group interaction that have driven CSCW evaluation in the past. A multifaceted evaluation framework is presented that approaches the problem from the relationships underlying joint awareness, communication, collaboration, coordination, and work coupling. Finally, recommendations for carrying out multifaceted evaluations of remote interaction are provided.

Co-located collaborators often work over physical tabletops with rich geospatial information. Previous research shows that people use gestures and speech as they interact with artefacts on the table and communicate with one another. With the advent of large multi-touch surfaces, developers are now applying this knowledge to create appropriate technical innovations in digital table design. Yet they are limited by the difficulty of building a truly useful collaborative application from the ground up. In this paper, we circumvent this difficulty by: (a) building a multimodal speech and gesture engine around the Diamond Touch multi-user surface, and (b) wrapping existing, widely-used off-the-shelf single-user interactive spatial applications with a multimodal interface created from this engine. Through case studies of two quite different geospatial systems Google Earth and Warcraft III we show the new functionalities, feasibility and limitations of leveraging such single-user applications within a multi user, multimodal tabletop. This research informs the design of future multimodal tabletop applications that can exploit single-user software conveniently available in the market. We also contribute (1) a set of technical and behavioural affordances of multimodal interaction on a tabletop, and (2) lessons learnt from the limitations of single user applications.

Abstract—In many domains, increased collaboration has lead to more innovation by fostering the sharing of knowledge, skills, and ideas. Shared analysis of information visualizations does not only lead to increased information processing power, but team members can also share, negotiate, and discuss their views and interpretations on a dataset and contribute unique perspectives on a given problem. Designing technologies to support collaboration around information visualizations poses special challenges and relatively few systems have been designed. We focus on supporting small groups collaborating around information visualizations in a co-located setting, using a shared interactive tabletop display. We introduce an analysis of challenges and requirements for the design of colocated collaborative information visualization systems. We then present a new system that facilitates hierarchical data comparison tasks for this type of collaborative work. Our system supports multi-user input, shared and individual views on the hierarchical data visualization, flexible use of representations, and flexible workspace organization to facilitate group work around visualizations. Index Terms—Information visualization, collaboration, co-located work, hierarchical data comparison. 1

Single Display Groupware (SDG) lets multiple co-located people, each with their own input device, interact simultaneously over a single communal display. While SDG is beneficial, there is risk of interference: when two people are interacting in close proximity, one person can raise an interface component (such as a menu, dialog box, or movable palette) over another person’s working area, thus obscuring and hindering the other’s actions. Consequently, researchers have developed special purpose interaction components to mitigate interference techniques. Yet is interference common in practice? If not, then SDG versions of conventional interface components could prove more suitable. We hypothesize that collaborators spatially separate their activities to the extent that they partition their workspace into distinct areas when working on particular tasks, thus reducing the potential for interference. We tested this hypothesis by observing co-located people performing a set of collaborative drawing exercises in an SDG workspace, where we paid particular attention to the locations of their simultaneous interactions. We saw that spatial separation and partitioning occurred consistently and naturally across all participants, rarely requiring any verbal negotiation. Particular divisions of the space varied, influenced by seating position and task semantics. These results suggest that people naturally avoid interfering with one another by spatially separating their actions. This has design implications for SDG interaction techniques, especially in how conventional widgets can be adapted to an SDG setting.

Mixed presence groupware (MPG) allows collocated and distributed teams to work together on a shared visual workspace. Presence disparity arises in MPG because it is harder to maintain awareness of remote collaborators compared to collocated collaborators. We examine the role of one’s body in collaborative work and how it affects presence disparity, articulating four design implications for embodiments in mixed presence groupware to mitigate the effects of presence disparity: embodiments should provide local feedback; they should visually portray people’s interaction with the work surface using direct input mechanisms; they should display fine-grain movement and postures of hand gestures, and they should be positioned within the workspace. We realize and evaluate these implications with VideoArms, an embodiment technique that captures and reproduces people’s arms as they work over large displays.

There is a large disparity between the rich physical interfaces of co-located arcade games and the generic input devices seen in most home console systems. In this paper we argue that a digital table is a conducive form factor for general co-located home gaming as it affords: (a) seating in collaboratively relevant positions that give all equal opportunity to reach into the surface and share a common view, (b) rich whole handed gesture input normally only seen when handling physical objects, (c) the ability to monitor how others use space and access objects on the surface, and (d) the ability to communicate to each other and interact atop the surface via gestures and verbal utterances. Our thesis is that multimodal gesture and speech input benefits collaborative interaction over such a digital table. To investigate this thesis, we designed a multimodal, multiplayer gaming environment that allows players to interact directly atop a digital table via speech and rich whole hand gestures. We transform two commercial single player computer games, representing a strategy and simulation game genre, to work within this setting. 1.

Collaborative Software Engineering (CSE) supports the fine-grained real-time development of software by teams of developers located anywhere on the Internet. In this paper we describe Caise, our CSE environment, and explore the ways in which such environments can benefit developers. We consider the roles of heuristic evaluation, log analysis and visualisation in quantifying the benefits of CSE.

The potential of tabletops to enable groups of people to simultaneously touch and manipulate a shared tabletop interface provides new possibilities for supporting collaborative learning. However, findings from the few studies carried out to date have tended to show small or insignificant effects compared with other technologies. We present the Collaborative Learning Mechanisms framework used to examine the coupling of verbal interactions and physical actions in collaboration around the tabletop and reveal subtle mechanisms at play. Analysis in this way revealed that what might be considered undesirable or harmful interactions and intrusions in general collaborative settings, might be beneficial for collaborative learning. We discuss the implications of these findings for how tabletops may be used to support children’s collaboration, and the value of considering verbal and physical aspects of interaction together in this way.

Abstract. We propose an analytic method to evaluate synchronous shared workspaces design. The method uses human-performance models, developed in the Human-Computer Interaction field, to make time predictions about collaborative actions performed in selected critical scenarios. We apply this method to two case studies: the design of a collaborative game and the redesign of a collaborative tool for software engineering requirements negotiation. The benefits and limitations of the method are discussed, as well as some implications for design. 1