We are interested in designing systems that support communication and collaboration among large groups of people over computer networks. We begin by asking what properties of the physical world support graceful human-human communication in face-to-face situations, and argue that it is possible to design digital systems that support coherent behavior by making participants and their activities visible to one another. We call such systems “socially translucent systems ” and suggest that they have three characteristics—visibility, awareness, and accountability—which enable people to draw upon their social experience and expertise to structure their interactions with one another. To motivate and focus our ideas we develop a vision of knowledge communities, conversationally based systems that support the creation, management and reuse of knowledge in a social context. We describe our experience in designing and deploying one layer of functionality for knowledge communities, embodied in a working system called “Babble, ” and discuss research issues raised by a socially translucent approach to design. Categories and Subject Descriptors: H.1.2 [Models and Principles]: User/Machine Systems—Human factors; Human information processing; H.5.2 [Information Interfaces and

This paper presents an overview of GroupKit, a groupware toolkit that lets developers build applications for synchronous and distributed computer-based conferencing. GroupKit was constructed from our belief that programming groupware should be only slightly harder than building functionally similar single-user systems. We have been able to significantly reduce the implementation complexity of groupware through the key features that comprise GroupKit. A runtime infrastructure automatically manages the creation, interconnection, and communications of the distributed processes that comprise conference sessions. A set of groupware programming abstractions allows developers to control the behaviour of distributed processes, to take action on state changes, and to share relevant data. Groupware widgets let interface features of value to conference participants to be easily added to groupware applications. Session managers⎯interfaces that let people create and manage their meetings⎯are decoupled from groupware applications and are built by developers to accommodate the group’s working style. Example GroupKit applications in a variety of domains have been implemented with only modest effort.

Current configuration management systems promote workspaces that isolate developers from each other. This isolation is both good and bad. It is good, because developers make their changes without any interference from changes made concurrently by other developers. It is bad, because not knowing which artifacts are changing in parallel regularly leads to problems when changes are promoted from workspaces into a central configuration management repository. Overcoming the bad isolation, while retaining the good isolation, is a matter of raising awareness among developers, an issue traditionally ignored by the discipline of configuration management. To fill this void, we have developed Palantr, a novel workspace awareness tool that complements existing configuration management systems by providing developers with insight into other workspaces. In particular, the tool informs a developer of which other developers change which other artifacts, calculates a simple measure of severity of those changes, and graphically displays the information in a configurable and generally non-obtrusive manner. To illustrate the use of Palantr, we demonstrate how it integrates with two representative configuration management systems.

The rich person-to-person interaction afforded by shared physical workspaces allows people to maintain up-to-the minute knowledge about others ’ interaction with the workspace. This knowledge is workspace awareness, part of the glue that allows groups to collaborate effectively. In real-time groupware systems that provide a shared virtual workspace, the possibilities for interaction are impoverished when compared with physical workspaces, partly because support for workspace awareness has not generally been a priority in groupware design. In this paper, we present the concept of workspace awareness as one key to supporting the richness evident in face-to-face interaction. We construct a conceptual framework that describes the elements and mechanisms of workspace awareness, and then show several widgets that can be embedded in relaxed-WYSIWIS groupware systems to support the maintenance of workspace awareness.

The concept of awareness has received increasing attention over the past several CSCW conferences. Although many awareness interfaces have been designed and studied, most have been limited deployments of research prototypes. In this paper we describe Sideshow, a peripheral awareness interface that was rapidly adopted by thousands of people in our company. Sideshow provides regularly updated peripheral awareness of a broad range of information from virtually any accessible web site or database. We discuss Sideshow's design and the experience of refining and redesigning the interface based on feedback from a rapidly expanding user community.

Concurrency control and group undo are important issues in the design of groupware, especially for interactive group editors. We present an improved version of an existing distributed algorithm for concurrency control that is based on operation transformations. Since the usability of the algorithm relies on its formal correctness, we present a set of necessary and sufficient conditions to be satisfied in order to ensure consistency in a replicated architecture. We identify desirable properties of operation transformations and show how our approach can be employed to implement group undo. The approach has been applied to build a prototypical group editor for text; some experiences gained are presented. Keywords Concurrency Control, Group Editors, Group Undo, Groupware, Interaction Model, Operation Transformation. INTRODUCTION Groupware systems, i.e., multi-user applications for cooperative work [2, 5], present remarkable challenges for application designers. Concurrency control and ...

Researchers in Computer Supported Cooperative Work have recently developed discount evaluation methods for shared-workspace groupware. Most discount methods rely on some understanding of the context in which the groupware systems will be used, which means that evaluators need to model the tasks that groups will perform. However, existing task analysis schemes are not well suited to the needs of groupware evaluation: they either do not deal with collaboration issues, do not use an appropriate level of analysis for concrete assessment of usability in interfaces, or do not adequately represent the variability inherent in group work. To fill this gap, we have developed a new modeling technique called Collaboration Usability Analysis. CUA focuses on the teamwork that goes on in a group task rather than the taskwork. To enable closer links between the task representation and the groupware interface, CUA grounds each collaborative action in a set of group work primitives called the mechanics of collaboration. To represent the range of ways that a group task can be carried out, CUA allows variable paths through the execution of a task, and allows alternate paths and optional tasks to be modeled. CUA’s main contribution is to provide evaluators with a framework in which they can simulate the realistic use of a groupware system

Shared physical workspaces allow people to maintain upto-the minute knowledge about others ’ interaction with the workspace. This knowledge is workspace awareness, part of the glue that allows groups to collaborate effectively. In this paper, we present the concept of workspace awareness as a key for groupware systems that wish to support the fluid interaction evident in face-to-face collaboration. We discuss why workspace awareness is difficult to support in groupware systems, and then present a conceptual framework that groupware designers can use as a starting point for thinking about and supporting awareness.

The emergence and widespread adoption of the World Wide Web offers a great deal of potential in supporting cross-platform cooperative work within widely-dispersed working groups. The Basic Support for Cooperative Work (BSCW) project at GMD is attempting to realise this potential through development of Web-based tools which provide cross-platform collaboration services to groups using existing Web technologies. This paper describes one of these tools, the BSCW Shared Workspace system---a centralised cooperative application integrated with an unmodified Web server and accessible from standard Web browsers. The BSCW system supports cooperation through `shared workspaces'; small repositories in which users can upload documents, hold threaded discussions, and obtain information on the previous activities of other users to coordinate their own work. The current version of the system is described in detail, including design choices resulting from use of the Web as a cooperation platform and f...

This article is a substantially expanded version of a report presented at the 1998 ACM CHI conference [Gutwin and Greenberg 1998]. Authors' addresses: C. Gutwin, Department of Computer Science, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan S7N 5A9, Canada; email: gutwin@cs.usask.ca; S. Greenberg, Department of Computer Science, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada; email: saul@cpsc.ucalgary.ca. Permission to make digital / hard copy of part or all of this work for personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication, and its date appear, and notice is given that copying is by permission of the ACM, Inc. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and / or a fee