Abstract not found

Introduction Our paper presents a model for supporting group interaction in large-scale virtual worlds 1 . The model provides generic techniques for managing interactions between various objects in such environments including humans and computer artefacts. Furthermore, the model is intended to be sufficiently flexible to apply to any system where a spatial metric can be identified (i.e. a way of measuring distance and orientation). Such applications might range from the obvious example of multi-user virtual reality through conferencing systems, collaborative hypermedia and even databases and information spaces. 1 The theory described in this paper is being developed as part of the COMIC project, an ongoing European ESPRIT Basic Research Action which aims to develop theories and techniques to support the development of future large scale CSCW systems. We would like to thank our fellow comedians for their discussions and comments. This paper has been

Workflow management is a technology that is considered strategically important by many businesses, and its market growth shows no signs of abating. It is, however, often viewed with skepticism by the research community, conjuring up visions of oppressed workers performing rigidly-defined tasks on an assembly line. Although the potential for abuse no doubt exists, worlcflow management can instead be used to help individuals manage their work and to provide a clear context for performing that work. A key challenge in the realization of this ideal is the reconciliation of workflow process models and software with the rich variety of activities and behaviors that comprise "real" work. Our experiences with the InConcert workflow management system are used as a basis for outlining several issues that will need to be addressed in meeting this challenge. This is intended as an invitation to CSCW researchers to influence this important technology in a constructive manner by drawing on research and experience. KEYWORDS: Workflow, business process reengineering.

We have developed a high-level and flexible framework for supporting the construction of multi-user user-interfaces. The framework is based on a generalized editing interaction model, which allows users to view programs as active data that can be concurrently edited by multiple users. It consists of several novel components including a refinement of both the Seeheim UIMS architecture and the distributed graphics architecture that explicitly addresses multi-user interaction; the abstractions of shared active variables and interaction variables, which allow users and applications to exchange information; a set of default collaboration rules designed to keep the collaboration-awareness low in multi- user programs; and a small but powerful set of primitives for overriding these rules. The framework allows users to be dynamically added and removed from a multi-user session, different users to use different user interfaces to interact with an application, the modules interacting with a particular user to execute on the local workstation, and program- mers to incrementally trade automation for flexibility. We have implemented the framework as part of a system called Suite. This paper motivates, describes, and illustrates the framework using the concrete example of Suite, discusses how it can be implemented in other kinds of systems, compares it with related work, discusses its shortcom- ings, and suggests directions for future work.

This dissertation analyzes the usefulness of existing "conventional" collaboration-transparency systems, which permit the shared use of legacy, single-user applications. I find that conventional collaboration-transparency systems do not use network resources efficiently, and they impose an inflexible, tightly coupled style of collaboration because they do not adequately support important groupware principles: concurrent work, relaxed WYSIWIS, group awareness, and inherently collaborative tasks. This dissertation proposes and explores solutions to those deficiencies. The primary goal of this work is to maintain the benefits of collaboration transparency while relieving some of its disadvantages. To that end, I present an alternate implementation approach that provides many features previously seen only in applications specifically designed to support cooperative work, called collaboration-aware applications. The new approach uses a replicated architecture, in which a copy of the application resides on each user's machine, and the users' input events are broadcast to each copy. I discuss solutions to certain key problems in replicated architectures, such as maintaining consistency, unanticipated sharing, supporting late-joiners, and replicating system resources (e.g., files, sockets, and random number generators). To enhance the collaborative usability of a legacy application, the new approach transparently replaces selected single-user interface objects with multi-user versions at runtime. There are four requirements of an application platform needed to implement this approach: process migration, run-time object replacement, dynamic binding, and the ability to intercept and introduce low-level user input events. As an instance of this approach, I describe its incorpor...

Recent years have seen a shift in perception of the nature of HCI and interactive systems. As interface work has increasingly become a focus of attention for the social sciences, we have expanded our appreciation of the importance of issues such as work practice, adaptation, and evolution in interactive systems. The reorientation in our view of interactive systems has been accompanied by a call for a new model of design centered around user needs and participation. This article argues that a new process of design is not enough and that the new view necessitates a similar reorientation in the structure of the systems we build. It outlines some requirements for systems that support a deeper conception of interaction and argues that the traditional system design techniques are not suited to creating such systems. Finally, using examples from ongoing work in the design of an open toolkit for collaborative applications, it illustrates how the principles of computational reflection and metaobject protocols can lead us toward a new model based on open abstraction that holds great promise in addressing these issues.

MMCC, the multimedia conference control program, is a window-based tool for connection management. It serves as an application interface to a wide-area network packet teleconferencing system, in which it is used not only to orchestrate multisite conferences, but also to provide local and remote audio and video control, and to interact with other conference-oriented tools that support shared workspaces. In this paper we document the design, operation and continued evolution of MMCC. We present MMCC's general architecture model, its connection control protocol and its relationship to other system components. This discussion raises issues about configuration management and the impact of conferencing over the Internet. Finally, we discuss MMCC's influence on current directions for research in multimedia connection management, and on our efforts to design a scalable Internet teleconferencing architecture.

The interaction history of a document can be modelled as a tree of command objects. This model not only supports recovery (undo/redo), but is also suitable for cooperation between distributed users working on a common document. Various coupling modes can be supported. Switching between modes is supported by regarding different versions of a document as different branches of the history. Branches can then be merged using a selective redo mechanism. Synchronous cooperation is supported by replicating the document state and exchanging command objects. Optimistic concurrency control can be applied, because conflicting actions can later be undone automatically.

A range of architectures have emerged which support realtime cooperative user interfaces. These architectures have tended to centralise the management of the interface and thus provide only limited support for user-centred development and interface tailoring. This paper considers the problems associated with the development of tailorable cooperative interfaces and proposes an architecture which allows such interfaces to be developed using an incremental, user-centred approach. The architecture presented in this paper has emerged within the context of a project investigating cooperative interface development for UK air traffic control. We conclude that the architecture is equally applicable to other Command and Control domains, where a shared information space forms the focus for the work taking place. KEYWORDS Multi-user interfaces, CSCW architectures, Command and Control systems, Database visualisation. INTRODUCTION The merging of computer and communications technology and the develop...

Over the last decade, Computer Supported Cooperative Work (CSCW) has emerged as an identifiable research area which focuses on the role of the computer in group work. CSCW is a generic term which combines the understanding of the nature of group working with the enabling technologies of computer networking, systems support and applications. This paper examines the classes of system which have emerged to support cooperative working. A framework for characterising and describing CSCW systems is presented and four major classes of cooperative system identified. Each of these classes of cooperative system are examined highlighting their general characteristics and applicability to CSCW. Contents 1. Introduction............................................................................. 2 2. A classification of CSCW systems ..................................................2 2.1 The classes of CSCW systems.................................................3 3. Message systems...................