LICRA: A replicated-data management algorithm for distributed synchronous groupware applications

Replicated data consistency is a key issue in the design of distributed real time groupware applications. In this paper, we propose a new protocol to cope with this problem. The proposed algorithm guarantees an optimal response time while ensuring data consistency at system quiescence. The originality of our proposition relies on the fact that neither locks nor clocks nor global information are required to establish data consistency. Instead, direct dependency relations between generated operations as well as operation transformation mechanism are used. The coupling of the above two mentioned mechanisms is shown to realize a good trade-off between the different requirements of groupware applications. Advantages of our approach are illustrated by comparing the algorithm to two well known optimistic concurrency control protocols for groupware applications: dOPT and ORESTE.     

Groupware Environments as Action Constitutive Resources: A Social Action Framework for Analyzing Groupware Technologies

Computer Supported Cooperative Work (CSCW) is a relatively new and dynamic field dealing with the development and use of groupware technologies in organizations. Several frameworks and models have been proposed for studying CSCW, each conveying a different perspective and theoretical basis. Although these frameworks have contributed much to our understanding of the field, they can be criticized for a lack of holistic understanding of the complex social activity that is constitutive of groupwork. This often leads to the failure of otherwise well designed CSCW applications. In this paper we take up this challenge and propose a social action framework for analyzing groupware technologies. The framework is based on Habermas's theory of social action and four action categories, and the idea that groupware applications serve as sets of rules and resources which mediate group interactions. We demonstrate the value of the framework by analyzing a wide range of existing groupware technologies for their appropriateness to specific groupwork situations in terms of their espoused or implicit assumptions of groupwork, and the action constitutive resources they provide. Our analysis points out that a host of current groupware applications can be fairly easily classified and examined by the way they are configured to support different types of social action. It also suggests that, when implementing groupware applications, developers should critically evaluate: (a) the need for supporting a rich variety of action types, (b) the possible role of computer support in the specific groupwork situations, and (c) the underlying assumptions of groupwork embedded in the groupware platform. Finally, we will discuss how the framework can inform future research and development in the field.     

An approach to information requirements specification for process control tasks

This paper discusses the need for designers of process plant supervisory systems to make greater effort in anticipating the information that operators require to carry out their duties. A method for dealing with this problem of information requirements specification in process plant design is proposed. This method translates a task analysis into a set of standard task elements from which standard sets of information, called ‘sub-goal templates’ can be derived. The resultant information requirements specification sets out the operators' information needs in the context of the operating goals that have to be attained. Early trials with the method indicate its promise, but highlight the need for its implementation in a computer tool to assist the designer. The features of such a tool and the further work necessary to develop and test the method are described.     

Groupware development support with technology patterns

Groupware development support should educate developers on how to design groupware applications and foster the reuse of proven solutions. Additionally, it should foster communication between developers and end-users, since they need a common language and understanding of the problem space. Groupware frameworks provide solutions for the development of groupware applications by means of building blocks. They have become a prominent means to support developers, but from our experience frameworks have properties that complicate their usage and do not sufficiently support groupware developers. We argue for a pattern approach to support the technical aspects of groupware development. Patterns describe solutions to recurring issues in groupware development. They serve as educational and communicative vehicle for reaching the above goals. In this article, we provide a pattern language focusing on technical issues during groupware development. Experiences when using the language in an educational setting and a product development setting have shown that the patterns are a supportive means for the proposed goals.     

ActiveX组件技术在网络课件中的应用

结合网络多媒体课件项目的开发,介绍ActiveX技术的工作机制与特点,主要分析了在网络多媒体课件设计中如何开发ActiveX组件,如何通过组件播放可执行文件的方法,并给出了部分关键程序。实际应用表明,该方法简单实用,性能可靠,对其他同类型的WEB应用的设计有一定的借鉴作用。     

F2FMI: A toolkit for facilitating face-to-face mobile interaction

The importance of mobile groupware systems resides in the specific tasks that they can perform and other systems cannot. On the one hand, groupware systems allow groups of users to work together providing facilities that single-user systems are unable to offer. On the other hand, unlike stationary systems, mobile systems allow users to work on the move. The intersection of these two technologies offers a new support for activities, such as spontaneous collaboration, that could be facilitated neither by stationary groupware systems nor by mobile single-user systems. However, implementations of this new support are uncommon, probably because of the high development effort required and the seemingly little benefit obtained. In this paper, we aim to reduce this effort by facilitating the development of mobile groupware applications that support such activities. Our proposal to achieve this objective involves the design and implementation of the Face-to-Face Mobile Interaction (F2FMI) toolkit, whose goal is to provide generic and reusable software components required in most cases. We expect this strategy to yield a higher variety of successfully deployed applications, which in turn will demonstrate the benefits of supporting this kind of interactions through mobile devices.     

Perceived critical mass effect on groupware acceptance

Groupware technologies have become an important part of the business computing infrastructure in many organizations, but many groupware applications, especially those requiring significant collaboration and cooperation among users, are still not adequately used. While the successful implementation of groupware depends on many different factors, achieving a ‘critical mass’ of users has been recognised as the key for groupware acceptance. By extending the technology acceptance model (TAM), this paper advances a groupware acceptance model that incorporates perceived critical mass as an independent variable for predicting groupware acceptance. The model is empirically evaluated using survey data collected from 385 students responding about their perception of Lotus Domino Discussion Databases. The results reveal that perceived critical mass had the largest total effect (direct and indirect) on intention to use groupware. Other relationships postulated in the model were also found to be significant. These findings corroborate the belief that it is essential to create a critical mass of users in the early stages of groupware implementation. A discussion of the implications of these findings for managers and researchers is also presented.     

WebSpec: a visual language for specifying interaction and navigation requirements in web applications

Web application development is a complex and time-consuming process that involves different stakeholders (ranging from customers to developers); these applications have some unique characteristics like navigational access to information, sophisticated interaction features, etc. However, there have been few proposals to represent those requirements that are specific to Web applications. Consequently, validation of requirements (e.g., in acceptance tests) is usually informal and as a result troublesome. To overcome these problems, we present WebSpec, a domain-specific language for specifying the most relevant and characteristic requirements of Web applications: those involving interaction and navigation. We describe WebSpec diagrams, discussing their abstraction and expressive power. With a simple though realistic example, we show how we have used WebSpec in the context of an agile Web development approach discussing several issues such as automatic test generation, management of changes in requirements, and improving the understanding of the diagrams through application simulation.     

Content-based management of video in a multimedia authoring environment

This paper describes architecture and implementation of a multimedia authoring environment which features content-based management of video.The goal of our work is to provide multimedia application developers with a useful video database, where they gather video materials from various sources, store them in a organized format, and use them in multimedia applications. The principal design concepts are that (1) it should have a flexible means to store video materials in a organized format so that video clips can be retrieved easily, and that (2) it should have a view to each application so that various applications can share the video materials.To meet these requirements we designed a multimedia authoring system based on a video object model. The video object model features (1) a method to attach annotations not only to scenes but also to things shot in the video, and (2) a method to define video clips independently from physical video data.Our experiences in using the system to develop a multimedia CAI application are also described to show the advantages of our system.     

PDM系统与群件系统的集成

在CIMS环境下,企业的产品信息管理主要由PDM来完成;而办公部门则使用群件系统作为协同工作办公自动化平台,要实现整个的信息集成,不可避免地要将PDM系统与群件系统集成起来,文中通过对PDM系统和群件系统主要功能的分析,总结出这两种系统集成的需求,内容和原理,并以具体的软件系统探讨了集成的实现。     

Using shared representations to improve coordination and intent inference

In groupware, users must communicate about their intentions and aintain common knowledge via communication channels that are explicitly designed into the system. Depending upon the task, generic communication tools like chat or a shared whiteboard may not be sufficient to support effective coordination. We have previously reported on a methodology that helps the designer develop task specific communication tools, called coordinating representations, for groupware systems. Coordinating representations lend structure and persistence to coordinating information. We have shown that coordinating representations are readily adopted by a user population, reduce coordination errors, and improve performance in a domain task. As we show in this article, coordinating representations present a unique opportunity to acquire user information in collaborative, user-adapted systems. Because coordinating representations support the exchange of coordinating information, they offer a window onto task and coordination-specific knowledge that is shared by users. Because they add structure to communication, the information that passes through them can be easily exploited by adaptive technology. This approach provides a simple technique for acquiring user knowledge in collaborative, user-adapted systems. We document our application of this approach to an existing groupware system. Several empirical results are provided. First, we show how information that is made available by a coordinating representation can be used to infer user intentions. We also show how this information can be used to mine free text chat for intent information, and show that this information further enhances intent inference. Empirical data shows that an automatic plan generation component, which is driven by information from a coordinating representation, reduces coordination errors and cognitive effort for its users. Finally, our methodology is summarized, and we present a framework for comparing our approach to other strategies for user knowledge acquisition in adaptive systems.     

Using Handheld Devices in Synchronous Collaborative Scenarios

In this paper we present a platform specially designed for groupware applications running on handheld devices. Common groupware platforms request desktop computers as underlying hardware platforms. The fundamentally different nature of handheld devices has a great impact on the platform, e.g. resource limitations have to be considered, the network is slow and unstable. Often, personal data are stored on handheld devices, thus mechanisms have to ensure privacy. These considerations led to the QuickStep platform. Sample applications developed with QuickStep demonstrate the strengths of the QuickStep environment.     

Developing groupware for requirements negotiation: lessons learned

Defining requirements is a complex and difficult process, and defects in the process often lead to costly project failures. There is no complete and well-defined set of requirements waiting to be discovered in system development. Different stakeholders: users, customers, managers, domain experts, and developers, come to the project with diverse expectations and interests. Requirements emerge in a highly collaborative, interactive, and interdisciplinary negotiation process that involves heterogeneous stakeholders. At the University of Southern California's Center for Software Engineering, we have developed a series of groupware implementations for the WinWin requirements negotiation approach. The WinWin approach involves having a system's success-critical stakeholders participate in a negotiation process so they can converge on a mutually satisfactory or win-win set of requirements. The WinWin groupware system, which has evolved over four generations, enables and facilitates heterogeneous stakeholder participation and collaboration. Each generation reflects an increase in our understanding of what is needed for successful WinWin groupware operations and technology support. The authors present the major lessons they learned during WinWin's development     

Construction of interaction observation systems for collaboration analysis in groupware applications

Interaction observation systems for groupware applications capture and process all the actions performed by users engaged in workgroups. These actions are then stored in log documents that enable the work process carried out by the users to be analyzed and the interaction between users to be studied. This article proposes an approach, based on ontological models, which is devised to help the developer of an observation system for a groupware application to structure and record user actions. In order to achieve this aim, we present a specific ontology that shapes the collaborative work process of the users so as to obtain an XML-based log document that stores all the actions carried out by the users and facilitates the subsequent analysis of the system usage and users’ behavior. This approach has been used to improve communication and collaboration capabilities in the COLLECE groupware application.     

Social activity indicators for groupware

Suppose you're a member of a few development teams, working with people who are geographically dispersed. You're using distributed groupware to work with your team mates. How do you decide when to work on a project and when to ignore requests to work on a project, when there are enough users on the groupware system to bother using it, who is available to answer a question, and which applications should get the most real estate on your screen? To help answer these questions, distributed groupware systems must indicate something about the social world they represent-who is on the system and what they are doing. User interfaces for groupware (or computer supported cooperative work (CSCW) applications) must therefore convey social information. It's energizing to know, for example, that your team mates are busy working away on a project. And it's nice to know when your friends or colleagues are available on a chat system. You might not need to know the semantics of the messages or documents involved, just that some activity is occurring. This is true for systems used by work groups as well as those used by an organization or a community of users. We think such social indicators should be a standard part of the CSCW user interface. On the basis of social psychology theory, we believe that a class of social indicator, which we call social activity indicators, is a simple, powerful way to improve user-interface functionality. Furthermore, social activity indicators are easy to build     

Context-aware trails [mobile computing]

The emergence of converged mobile devices with a wide range of computing, communications, entertainment, and sensing capabilities represents a major step in the evolution of wireless computing. Such devices increasingly shift the decision-making power from the user to the machine, which has the capacity to be better informed about the current environment and can respond more quickly. A trail is a collection of locations, together with associated information about these locations and a recommended order for visiting them. Mobile, context-aware trails-based applications range from single-user systems that focus on individual daily activities to multimedia groupware that supports a wide collection of user requirements. The trails metaphor makes it possible to explore adaptive characteristics common to all mobile, context-aware applications. Adaptation in this context involves altering the set of interest points on a trail and their visiting order with timeliness, accuracy, and relevance while remaining in tune with user expectations.     

室内定位方法综述

近年来,随着情景感知、环境智能等应用需求不断增加,对用户位置信息精度的要求也在不断提高。因室内环境复杂、缺乏统一的基础性架构等因素,室内定位方法逐渐成为用户定位领域的研究热点。考虑到室内定位方法的基础架构、位置精度、方法普适性等因素,将现有的室内定位方法分成3大类:基于特定设备的定位方法、基于WIFI的定位方法和基于移动传感器的定位方法。针对具体定位算法及不同算法的性能、特点和优劣等进行探讨和分析,最后总结当前室内定位方法领域的研究现状,并简要介绍该领域未来的研究方向及发展趋势。     

群件技术在质量管理中的应用研究

本文介绍了一些典型的群件技术和一个以取得ＩＳＯ９０００质量认证为目的的质量管理方法，对群件技术和质量管理过程两者的结合作了探讨，并以两个流行的群件软件ＬｏｔｕｓＮｏｔｅｓ和ＭｉｃｒＯｓｏｆｔＮｅｔＭｅｅｔｉｎｇ为例说明了群件技术在质量管理过程的作用。     

A family of experiments to investigate the effects of groupware for software inspection

It is widely accepted that the inspection of software artifacts can find defects early in the development process and gather information on the quality of the evolving product. However, the inspection process is resource-intensive and involves tedious tasks, such as searching, sorting, and checking. Tool support for inspections can help accelerating these tasks and allows inspectors to concentrate on tasks particularly needing human attention. Only few tools are available for inspections. We have thus developed a set of groupware tools for both individual defect detection and inspection meetings to lower the effort of inspections and to increase their efficiency. This paper presents the Groupware-supported Inspection Process (GrIP) and describes tools for inspecting software requirements. As only little empirical work exists that directly compares paper-based and tool-based software inspection, we conducted a family of experiments in an academic environment to empirically investigate the effect of tool support regarding defect detection and inspection meetings. The main results of our family of experiments regarding individual defect detection are promising: The effectiveness of inspectors and teams is comparable to paper-based inspection without tool support; the inspection effort and defect overlap decreases significantly with tool support, while the efficiency of inspection teams increases considerably. Regarding tool support for inspection meetings the main findings of the experiments are that tool support considerably lowers the meeting effort, supports inspectors in identifying false positives, and reduces the number of true defects lost during a meeting. The number of unidentified false positives is still quite high.