Users of synchronous groupware systems act both as individuals and as members of a group, and designers must try to support both roles. However, the requirements of individuals and groups often conflict, forcing designers to support one at the expense of the other. The tradeoff is particularly evident in the design of interaction techniques for shared workspaces. Individuals demand powerful and flexible means for interacting with the workspace and its artifacts, while groups require information about each other to maintain awareness. Although these conflicting requirements present real problems to designers, the tension can be reduced in some cases. We consider the tradeoff in three areas of groupware design: workspace navigation, artifact manipulation, and view representation. We show techniques such as multiple viewports, process feedthrough, action indicators, and view translations that support the needs of both individuals and groups.

carl.gutwin, reagan.penner, kevin.schneider @ usask.ca Open-source software development projects are almost always collaborative and distributed. Despite the difficulties imposed by distance, these projects have managed to produce large, complex, and successful systems. However, there is still little known about how open-source teams manage their collaboration. In this paper we look at one aspect of this issue: how distributed developers maintain group awareness. We interviewed developers, read project communication, and looked at project artifacts from three successful open source projects. We found that distributed developers do need to maintain awareness of one another, and that they maintain both a general awareness of the entire team and more detailed knowledge of people that they plan to work with. Although there are several sources of information, this awareness is maintained primarily through text-based communication (mailing lists and chat systems). These textual channels have several characteristics that help to support the maintenance of awareness, as long as developers are committed to reading the lists and to making their project communication public.

Gestural communication is an important part of shared work, both in face-to-face settings and distributed environments. However, gestures in groupware are often difficult to see and interpret because of disruptions to their motion caused by network jitter. One way to improve the visibility of remote gestures is by using traces--- visualizations of the last few moments' of a remote pointer's motion. We carried out an experiment to test the effectiveness of traces in helping people interpret gestures. We found that telepointer traces dramatically improved people's accuracy and confidence in their decisions as jitter delays grew larger. Our results suggest that telepointer traces and other visualizations of interaction history can be used to enrich communication among remote collaborators.

Introduction Although the phrase team cognition suggests something that happens inside people's heads, teams are very much situated in the real world, and there are a number of things that have to happen out in that world for teams to be able to think and work together. This is not just spoken communication. Depending on the circumstances, effective team cognition includes things like using environmental cues to establish a common ground of understanding, seeing who is around and what they are doing, monitoring the state of artefacts in a shared work setting, noticing other people's gestures and what they are referring to, and so on (Clark, 1996; Hutchins, 1996). In this chapter, we will argue that awareness of other group members is a critical building block in the construct of team cognition, and consequently that computational support for awareness in groupware systems is crucial for supporting team cognition in distributed groups. Our main message is that: ... for people to sust

This paper proposes a framework for describing, comparing and understanding visualization tools that provide awareness of human activities in software development. The framework has several purposes – it can act as a formative evaluation mechanism for tool designers; as an assessment tool for potential tool users; and as a comparison tool so that tool researchers can compare and understand the differences between various tools and identify potential new research areas. We use this framework to structure a survey of visualization tools for activity awareness in software development. Based on this survey we suggest directions for future research.

Virtual embodiments of people in groupware systems provide a wealth of information to others in the group. They allow for explicit gestural communication, and they provide implicit awareness information about people’s locations and activities. However, the constraints of current networked groupware limit the effectiveness of these kinds of communication. This paper investigates how embodiments can be augmented with traces – visualizations of past movements – to help others perceive and interpret bodily communication more clearly and more accurately. The paper presents a case study of traces applied to telepointers, and gives several examples of how the concept can be used to improve interaction effectiveness in groupware. Key words: Real-time groupware, groupware usability, awareness, interaction histories, edit wear, traces. 1

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.

Abstract. Network delays are a fact of life when using real-time groupware over a wide area network such as the Internet. This paper looks at how network delays affect closelycoupled group work in real-time distributed groupware. We first determine the types and amounts of delay that can happen on the Internet, and then identify typesof collaborative interactions that are affected by delay. We then examine two interaction types more closely: predicting others ' movements, and coordinating shared access to artifacts. We earned out experiments to measure the effects of two kinds of delay (latency and jitter). When these interactions are isolated and repeated, we found that even small delays can lead to significant increases in completion time and errors. Although people in real-world tasks are often able to adapt their actions to accommodate network delays, we conclude that designing groupware to minimise the effects of delay can improve usability for closely-coupled collaboration.

This paper examines the instruments and procedures found on state-of-the-art commercial airline flight decks. It argues that the flight deck as a whole should be viewed as a cognitive system and shows how design decisions may affect patterns of information flow which, in turn, produce cognitive consequences for the flight deck system. Some notable successes and persistent problems are described and a set of design principles that distinguish the successes from failures are presented. Finally, the application of the design principles to long-standing problems illustrates how these principles can lead to new instruments with desirable system properties.

Groupware that provides a distributed shared workspace is becoming more and more common. However, it is often difficult in these systems to maintain awareness of other people's actions and activities. One reason for this difficulty is that people's representations in groupware are neither as noticeable nor as expressive as their bodies in the real world. The hypothesis in this research is that making people's actions easier to see will improve awareness, communication, and coordination in collaborative tasks. I propose as the solution to the problem the idea of traces--- visualizations of people's interaction with the shared workspace. Traces differ from previous interaction history systems in that they are oriented around people and their actions, rather than on artifacts and the changes made to them. This paper describes the idea of traces, and then describes two applications of the idea: first, telepointer trails that made gestures persistent, and second, location tracks that record people's paths as they move and work in the shared workspace. Initial user feedback suggests that both techniques are valuable for certain kinds of collaborative situations.