The paper outlines an approach to CSCW systems design based on the concept of `coordination mechanisms.' The concept of coordination mechanisms has been developed as a generalization of phenomena described in empirical investigations of the use of artifacts for the purpose of coordinating cooperative activities in different work domains. On the basis of the evidence of this corpus of empirical studies, the paper outlines a theory of the use of artifacts for coordination purposes in cooperative work settings, derives a set of general requirements for computational coordination mechanisms, and sketches the architecture of Ariadne, a CSCW infrastructure for constructing and running such malleable and linkable computational coordination mechanisms.

The development of schemes to support group work, whether behavioral methods or new technologies like groupware, should be based on detailed knowledge about how groups work, what they do well, and what they have trouble with. Such data can be used to suggest what kinds of tools people might need as well as to provide a baseline for evaluating the effects of schemes for improvement. We present details of how real groups engage in a representative collaborative task- early software design meetings- to provide such knowledge. We studied 10 design meetings from four projects in two organizations. The meetings were videotaped, transcribed, and then analyzed using a coding scheme that looked at participants ' problem solving and the activities they used to coordinate and manage themselves. We also analyzed the structure of their design arguments. We found, to our surprise, that although the meetings differed in how many issues were covered they were strikingly similar in both how people spent their time and in the sequential

Despite intense and wide-spread research in both virtual environments (VEs) and usability, the exciting new technology of VEs has not yet been closely coupled with the important characteristic of usability -- a necessary coupling if VEs are to reach their full potential. Although numerous methods exist for usability evaluation of interactive computer applications, these methods have well-known limitations, especially for evaluating VEs. Thus, there is a great need to develop usability evaluation methods and criteria specifically for VEs. Our goal is to increase awareness of the need for usability engineering of VEs and to lay a scientific foundation for developing high-impact methods for usability engineering of VEs. The first step in our multi-year research plan has been accomplished, yielding a comprehensive multi-dimensional taxonomy of usability characteristics specifically for VEs. This taxonomy was developed by collecting and synthesizing information from literature, conferences, World Wide Web (WWW) searches, investigative research visits to top VE facilities, and interviews of VE researchers and developers. The taxonomy consists of four main areas of usability issues: Users and User Tasks in VEs, general user and task characteristics and types of tasks in VEs

The debate on the language/action perspective has been exciting the CSCW field for almost ten years. In this paper we recall the most relevant issues raised in it, we also propose a new exploitation of the language/action perspective considering it from the viewpoint of understanding the complexity of communication within work processes and the situatedness of work practices. On this basis we have defined a new conversation model, the Milan Conversation Model, and we are designing a new conversation handler implementing it.

Abstract. An activity is inseparably bound up with time, and interdependent cooperative activities thus need to be coordinated in time. The nature of time is therefore an ever-present issue in the design of computer systems supporting coordination. Based on Activity Theory this paper defines the concept of Temporal Coordination. Then, based on in-depth studies of the socio-temporal aspects of coordinating cooperative work at hospitals, the paper explores this notion of temporal coordination. This analysis identifies some of the highly intertwined temporal problems, constraints, interests, and conflicts, which arise when work subject to temporal limits is to be coordinated. The paper then introduces the PATIENT SCHEDULER, which is a prototype designed during this project to illustrate how aspects of temporal coordination can be supported by computer technology.

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In current workflow and groupware systems, there is a gap between formal and informal coordination mechanisms. To fill the gap, flexible coordination support covers the whole spectrum of informal and formal coordination mechanisms. In this paper, a flexible coordination model integrating formal and informal coordination mechanisms is presented. Methods of using cooperative hypermedia concepts to uniformly model all objects representing coordination mediums and shared artifacts are described. Using the proposed model and methods, a cooperative hypermedia system (CHIPS), that offers flexible coordination support has been implemented. An application example of the system shows how a set of tasks and different coordination mechanisms are integrated into a cooperative process. This work demonstrates that cooperative hypermedia can serve as a bridge to close the gap. Keywords: Cooperative hypermedia, groupware, coordination, workflow, CHIPS INTRODUCTION Recently, there is a growing intere...

. This paper proposes a model for integrated CSCW systems, the model of Objectoriented Activity Support OOActSM. In contrast to existing systems for the support of collaborativework, the model aims at the integrated support of all aspects of CSCW in a single frame system. The major properties of our model are the use of #activity" as the basic concept and the use of object-oriented mechanisms for providing solutions of typical CSCW problems. I demonstrate how all major aspects of current CSCW systems can be supported and integrated with each other in our model. Key words: Integrated CSCW, activity support, object-oriented paradigm, work#ow support, activity design 1. Introduction Nearly all CSCW systems whichhave been developed so far concentrate on a more or less narrow sub#eld of cooperativework. Examples of these sub#elds are work- #ow speci#cation, electronic meetings, or collaborative editing. As a consequence, users are forced to employ several di#erent CSCW application system...

We investigate how delayed communication affects the dynamic formation of groups in distributed systems, where all decision-making agents join the same group because each expects to improve its own performance. For example, distributed job schedulers may form a group to utilize the idle resources of other members within the group. Forming a group is a search problem and we examine agents which use the feedback mechanism of stochastic learning automata to carry out this search. Although a group formation may have the potential for synergy, the agents must successfully coordinate their actions within the group relevant to the application. For example, job schedulers who form a group must still balance the load among the shared resources; that is, the collective actions of the schedulers need to be coordinated and greedy schedulers who all pick the same processor may not be successful. Agents may find that working alone is more desirable since their actions need not be coordinated and the r...

The research into the Ariadne system- and its coordination language HOPLa- aims to provide generic support for hybrid collaborative processes. These are complex information processing tasks involving coordinated contributions from multiple people and tools. Ariadne should applicable for a broad spectrum of these processes and actively support people in working in these processes and in defining and managing. A key design issue is flexibility. It should be easy for users to model and perform new (kinds of) processes even if this happens during the work on the process itself. Processes in Ariadne combine a shared workspace with the ability to define tasks and to coordinate their execution. The workspace uses a tree-like data model and can hold arbitrarily structured data. It is self-descriptive which means that it not only holds actual data but also the constraints (i.e. type definitions) that govern its structure. The definition of the way of working in a process can be blended into the workspace. Nodes in the workspace can be marked as tasks to be performed. Aditional coordination operators and constraints e.g. on time or performer of a task can be attached. Ariadne keeps track of the execution state of each process and uses this for support. When tasks are to be performed, actors are notified and results of the work are stored again in the workspace. The execution state of the process is stored in the workspace too, so that processes are self-contained.