Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.

This article provides a cognitive analysis of how people navigate in the computer medium. As the complexity of computerized information systems increases, interface designers face the formidable challenge of supporting navigation within these systems to allow users to quickly obtain relevant information. Instead of focusing on the comparison of a small subset of proposed techniques for aiding navigation, this study investigates how people handle navigation within the natural context of a familiar computer environment and reveals cognitive processes that can be better supported to aid navigation. The results of a field study and a field experiment converge to support previous navigation-related theories and contribute to a pattern of navigation behavior that has been noticed in domains like anesthesiology and nuclear power. This article describes the characteristics of the computer medium that influence people's ability to navigate, discusses typical navigation problems that arise in this medium, and describes how designers can aid navigation, based on an analysis of how computer users change their behavior and adapt to computer systems to overcome navigation-related problems.

In this paper, we describe the coordinative anomaly response processes of functionally distinct teams who encountered a space shuttle anomaly at the beginning of a shuttle mission. Anomaly response processes were observed as two distinct teams considered how to modify mission plans in response to the anomaly. We analyzed multiple coordinative and independent activities that occurred across the teams over several days until the space shuttle safely returned. Our analysis of this case captures how the processes of anomaly response become distributed across a set of functionally distinct teams. The analysis identifies the demands that arise as anomaly response is distributed and reveals how interactions among distinct teams can make anomaly response robust in the face of uncertainty and risk. AS WE WERE IN THE PROCESS OF OBSERVING NOMINAL OPERATIONS IN SPACE SHUTTLE MISSIONControl, an anomaly occurred on the space shuttle during the ascent phase of shuttle mission STS-76 (March 1996). As flight controllers monitored the stream of telemetry data, they recognized indications of a leak in one of three hydraulics systems. This anomaly triggered multiple activities and analyses that spread over multiple days and multiple teams as mission control personnel evaluated the anomaly and considered whether and how to modify mission plans.In this article, we present the findings from our unique opportunity to observe the response to a naturally occurring space shuttle anomaly from beginning to end. We provide an analysis of the anomaly response processes that occurred during the STS-76 shuttle mission, focusing on how the distinct teams interacted and coordinated their efforts. We shadowed the Mechanical, Maintenance, Arm, and Crew Systems (MMACS) mission control team during the launch, ascent, orbit, and descent phases of this shuttle mission. These observations were made possible as part of a project to study how mission control works as a distributed cognitive system performing anomaly response (Malin et al.

INTRODUCTIONRapid socio-technical change is underway in the world of work. Mobile technology and access to broadband internet have evolved enough that they now provide the opportunity to work anytime, from almost anywhere. Many companies are using these capabilities to send some of their employees home to work, effectively lowering real estate and commuting costs, and attracting a diverse set of workers. Workers are often members of globally distributed teams, who collaborate to create complex, interconnected webs of dynamic information. Video, audio, and databases of images are entering the world of work, along with Web 2.0 applications like wikis, podcasts, blogs, and social networking sites. The convergence of these trends is creating significant changes in the workplace.The Xerox Future of Work team conducted studies in 2008 to explore the impact of these changes on the nature of work. Using an ethnographic approach, the team conducted interviews and observations of people who work at home or on the go. The people studied were already working at the forefront of these trends, participating in alternative work scenarios that didn't include office cubicles, and using new tools and technology to support these new kinds of work. The team studied how participants used technology to coordinate their work, how they balanced and/or integrated work and personal life, and how the nature EPIC 2009, pp. 197-208, ISBN 0-9799094-2-4.

This paper contrasts cooperative work in two cases of distributed anomaly response, both from space shuttle mission control, to learn about the factors that make anomaly response robust. In one case (STS-76), flight controllers in mission control recognized an anomaly that began during the ascent phase of a space shuttle mission, analyzed the implications of the failure for mission plans, and made adjustments to plans (the flight ended safely). In this case, a Cooperative Advocacy approach facilitated a process in which diverse perspectives were orchestrated to provide broadening and cross-checks that reduced the risk of premature narrowing. In the second case (the Columbia space shuttle accident-STS-107), mission management treated a debris strike during launch as a side issue rather than a safety of flight concern and was unable to recognize the dangers of this event for the flight which ended in tragedy. In this case, broadening and cross-checks were missing due to fragmentation over the groups involved in the anomaly response process. The comparison of these cases points to critical requirements for designing collaboration over multiple groups in anomaly response situations.