Knowledge awareness in CSCL: A psychological perspective

In this paper, a specific group awareness approach for CSCL settings, namely knowledge awareness, is presented. We classify knowledge awareness in relation to already well-established concepts like shared mental models, common ground, and transactive memory system in order to provide a comprehensive definition of this approach. The functionality of knowledge awareness tools aiming at fostering knowledge awareness is conceptualized in a cyclical model. Three application scenarios are presented to illustrate how knowledge awareness tools work in three different tasks. All these knowledge awareness tools have been found to be effective, that is all tools could foster knowledge awareness and led to increased learning performance.     

Group awareness in CSCL environments

Group awareness is an emerging topic in research on computer-supported collaborative learning (CSCL). It covers the knowledge and perception of behavioral, cognitive, and social context information on a group or its members. A central aim of CSCL-related research on group awareness is the development of tools that implicitly guide learners’ behavior, communication, and reflection by the presentation of information on a learning partner or a group. This special issue comprises six empirical contributions and a concluding discussion that present a broad spectrum of current research on this topic including behavioral, cognitive and social group awareness. An introductory outline of how group awareness is formed, processed and translated in action along the contributions is intended to integrate the diverse research activities on group awareness in CSCL environments.     

Facilitating peer knowledge modeling: Effects of a knowledge awareness tool on collaborative learning outcomes and processes

We report an empirical study where we investigated the effects, on the collaborative outcomes and processes, of a cognition-related awareness tool providing learners with cues about their peer’s level of prior knowledge. Sixty-four university students participated in a remote computer-mediated dyadic learning scenario. Co-learners were provided (or not) with a visual representation of their peer’s level of prior knowledge through what we refer to as a knowledge awareness tool (KAT). The results show that, providing co-learners with objective cues about the level of their peer’s prior knowledge positively impacts learning outcomes. In addition, this effect seems to be mediated by the fact that co-learners provided with these objective cues become more accurate in estimating their partner’s knowledge - accuracy that predicts higher outcomes. Analyses on the process level of the verbal interactions indicate that the KAT seems to sensitize co-learners to the fragile nature of their partner’s as well as their own prior knowledge. The beneficial effect of the KAT seems to mainly rely on this induction of epistemic uncertainty that implicitly triggers compensation socio-cognitive strategies; strategies that appear to be beneficial to the learning process.     

Online collaborative learning in dyads: Effects of knowledge distribution and awareness

Research on collaborative learning traditionally assumes a certain degree of symmetry between the learning partners in terms of both their learning-relevant traits and their individual learning outcomes. However, if one collaborative partner is clearly more able, skilled, or knowledgeable than the other partner, then it remains unclear who profits more from the collaboration. The present study aimed to explore this issue by manipulating symmetry in prior knowledge within small groups of online learners (dyads) and measuring their problem-solving efficiency and incidental learning gain on an individual and dyad level. Awareness of this symmetry/asymmetry was manipulated, too, to discern it as a potential moderator. Dyads with symmetrical and asymmetrical prior knowledge performed equally well on most measures. Moreover, on average, the more and the less knowledgeable partners in the asymmetrical conditions had equal learning gains. However, while in dyads with symmetrical knowledge learning gains were correlated between the partners, in the asymmetrical dyads they were not. Awareness of symmetry/asymmetry did not act as a moderator, but, overall, dyads with awareness of each other's knowledge learned more from each other than dyads without such awareness. The benefit of awareness was, however, specific to the learning content exposed via awareness. We conclude that researchers and practitioners should be careful when choosing or assigning collaborative partners to each other, as only for partners with symmetrical prior knowledge can a symmetrical increase in knowledge be expected. We further discuss the implications of these findings for research on knowledge awareness and collaboration.     

Self-stabilizing group communication in directed networks

This paper presents the first self-stabilizing group membership service, multicast service, and resource allocation service for directed networks. The first group communication algorithm is based on a token circulation over a virtual ring. The second algorithm is based on construction of distributed spanning trees. In addition, a technique is presented that emulates, in a self-stabilizing fashion, any undirected communication network over strongly connected directed networks, is presented. A resource allocation asynchronous algorithm for strongly connected directed networks is presented.Received: 23 July 2003, Published online: 29 June 2004Partially supported by NSF Award CCR-0098305, IBM faculty award, STRIMM consortium, and Israel ministry of defense.     

Dynamic group communication

Group communication is the basic infrastructure for implementing fault-tolerant replicated servers. While group communication is well understood in the context of static groups (in which the membership does not change), current specifications of dynamic group communication (in which processes can join and leave groups during the computation) have not yet reached the same level of maturity. The paper proposes new specifications – in the primary partition model – for dynamic reliable broadcast (simply called “reliable multicast”), dynamic atomic broadcast (simply called “atomic multicast”) and group membership. In the special case of a static system, the new specifications are identical to the well known static specifications. Interestingly, not only are these new specifications “syntactically” close to the static specifications, but they are also “semantically” close to the dynamic specifications proposed in the literature. We believe that this should contribute to clarify a topic that has always been difficult to understand by outsiders. Finally, the paper shows how to solve atomic multicast, group membership and reliable broadcast. The solution of atomic multicast is close to the (static) atomic broadcast solution based on reduction to consensus. Group membership is solved using atomic multicast. Reliable multicast can be efficiently solved by relying on a thrifty generic multicast algorithm. Andrée Schiper graduated in Physics from the ETHZ in Zurich in 1973 and received the PhD degree in Computer Science from the EPFL (Federal Institute of Technology in Lausanne, Switzerland) in 1980. He has been a professor of computer science at EPFL since 1985, leading the Distributed Systems Laboratory. During the academic year 1992–1993, he was on sabbatical leave at the University of Cornell, Ithaca, New York, and in 2004-2005 at the Ecole Polytechnique near Paris. His research interests are in the area of dependable distributed systems, middleware support for dependable systems, replication techniques (including for database systems), group communication, distributed transactions, and, recently MANETs (mobile ad-hoc networks). From 2000 to 2002, he was the chair of the steering committee of the International Symposium on Distributed Computing (DISC). He has taken part in several European projects. He is currently a member of the editorial board of Distributed Computing, and of IEEE Transactions on Dependable and Secure Computing.     

Exploring gender and gender pairing in the knowledge elaboration processes of students using computer-supported collaborative learning

The aim of the study is to investigate the influence of gender and gender pairing on students’ learning performances and knowledge elaboration processes in Computer-Supported Collaborative Learning (CSCL). A sample of ninety-six secondary school students, participated in a two-week experiment. Students were randomly paired and asked to solve several moderately structured problems concerning Newtonian mechanics. Students’ pretest and posttest performances were analyzed to see whether students’ gender and the gender pairing (mixed or single-gender) were significant factors in their problem solving learning in CSCL. Students’ online interactions were also analyzed to unravel the dynamic process of individual knowledge elaboration. The multilevel analyses revealed that a divergent pattern of knowledge elaboration was a significant predictor for students’ learning achievement, and in mixed-gender dyads students’ knowledge elaboration processes were more inclined to diverge from each other. Moreover, females in single-gender dyads significantly outperformed females in mixed-gender dyads. But this was not the case for male students.     

Enhancing group communication with self-manageable behavior

Group communication protocols (GCPs) play an important role in the design of modern distributed systems. A typical GCP exchanges control messages to provide message delivery guarantees, and a key point in the configuration of such a protocol is to establish the right trade-off between message overhead and delivery latency. This trade-off becomes even a greater challenge in systems where computing resources and application requirements may change at runtime. In such scenarios, the configuration of a GCP must be continuously re-adjusted to attain certain performance goals, or to adapt to current resource availability. This paper addresses this challenge by proposing self-managing mechanisms based on feedback control theory to a GCP especially designed to be self-manageable; in the proposed protocol, message overhead and delivery latency can be adjusted at runtime to follow some new operating set-point. The evaluation performed under varied scenarios shows the effectiveness of our approach.     

Group awareness and self-presentation in computer-supported information exchange

A common challenge in many situations of computer-supported collaborative learning is increasing the willingness of those involved to share their knowledge with other group members. As a prototypical situation of computer-supported information exchange, a shared-database setting was chosen for the current study. This information-exchange situation represented a social dilemma: while the contribution of information to a shared database induced costs and provided no benefit for the individual, the entire group suffered when all members decided to withhold information. In order to alleviate the information-exchange dilemma, a group-awareness tool was employed. It was hypothesized that participants would use group awareness for self-presentational purposes. For the examination of this assumption, the personality variable ‘protective self-presentation’ (PSP) was measured. An interaction effect of group awareness and PSP was found: when an awareness tool provided information concerning the contribution behavior of each individual, this tool was used as a self-presentation opportunity. In order to understand this effect in more detail, single items of the PSP-scale were analyzed.     

Beyond threaded discussion: Representational guidance in asynchronous collaborative learning environments

Although most online learning environments are predominately text based, researchers have argued that representational support for the conceptual structure of a problem would address problems of coherence and convergence that have been shown to be associated with threaded discussions and more effectively support collaborative knowledge construction. The study described in this paper sets out to investigate the merits of knowledge mapping representations as an adjunct to or replacement for threaded discussion in problem solving by asynchronously communicating dyads. Results show that users of knowledge maps created more hypotheses earlier in the experimental sessions and elaborated on them more than users of threaded discussions. Participants using knowledge maps were more likely to converge on the same conclusion and scored significantly higher on post-test questions that required integration of information distributed across dyads in a hidden profile design, suggesting that there was greater collaboration during the session. These results were most consistent when a knowledge map with embedded notes was the primary means of interaction rather than when it augmented a threaded discussion.     

A scalable framework for mobile real-time group communication services

A scalable framework for mobile real-time group communication services is developed in this paper. Examples for possible applications of this framework are mobile social networks, mobile conference calls, mobile instant messaging services, and mobile multi-player on-line games. A key requirement for enabling a real-time group communication service is the tight constraint imposed on the call delivery delay. Since establishing such communication service for a group of independent mobile users under a tight delay constraint is NP-hard, a two-tier architecture is proposed, that can meet the delay constraint imposed by the real-time service requirement for many independent mobile clients in a scalable manner. This goal is achieved by two dimensional partition of the space, first by organization and then geographically. Both the time and memory complexity associated with the location management of N mobile users are O(N) for the location management provided by the proposed framework, while a distributed scheme requires O(N²) for both time and memory complexity.     

Strategies for collaborative writing and phases of knowledge construction in CSCL environments

Within the framework of research that describes the processes of collaborative knowledge construction in computer-supported collaborative learning (CSCL) environments, the present work has three objectives: (i) the identification of the strategies of six small groups of university students for the elaboration of written products in a CSCL environment; (ii) seek relations between the identified writing strategies and the processes and phases of collaborative knowledge construction in the groups; and (iii) relate these strategies and phases with the learning results obtained by the groups. We carried out a multiple-case study, with the analysis of four different didactic sequences, in two different virtual learning and teaching settings. In each setting, three student groups were studied, where each had to collaboratively develop between four and eight written products. For all the studied groups, the analysis enabled the identification of five types of strategies in the preparation of the elaboration of written products, and four types of phases of collaborative knowledge construction, which are interrelated and also connected with the grades that the groups obtained in each case.     

Group awareness of social and cognitive performance in a CSCL environment: Effects of a peer feedback and reflection tool

A peer feedback tool (Radar) and a reflection tool (Reflector) were used to enhance group performance in a computer-supported collaborative learning environment. Radar allows group members to assess themselves and their fellow group members on six traits related to social and cognitive behavior. Reflector stimulates group members to reflect on their past, present and future group functioning, stimulating them to set goals and formulate plans to improve their social and cognitive performance. The underlying assumption was that group performance would be positively influenced by making group members aware of how they, their peers and the whole group perceive their social and cognitive behavior in the group. Participants were 108 fourth-year high school students working in dyads, triads and groups of four on a collaborative writing task, with or without the tools. Results demonstrate that awareness stimulated by the peer feedback and reflection tools enhances group-process satisfaction and social performance of CSCL-groups.     

The educational impact of metacognitive group coordination in computer-supported collaborative learning

Group coordination is a crucial component for successful collaborative learning, but is hard to achieve in an online learning environment. A web-based group coordination tool was developed based on metacognitive scaffolding principles for the study. The tool was implemented in an online course for a group project and its effects were investigated. A total of 59 students formed into 20 groups participated in and completed a project while being guided with the tool. Based on response rate to metacognitive prompts of the tool, groups were categorized as Active Metacognitive Team (AMT, n = 30) or Passive Metacognitive Team (PMT, n = 29). AMT showed higher positive interdependence than PMT at the end of the project. AMT perceived reciprocal help among group members while PMT did not. AMT also evaluated its group process higher than PMT did. These results show that groups who more actively used the coordination support tool established positive interdependence, engaged in positive interactions, and had enhanced group productivity.     

Social networks,communication styles,and learning performance in a CSCL community

The aim of this study is to empirically investigate the relationships between communication styles, social networks, and learning performance in a computer-supported collaborative learning (CSCL) community. Using social network analysis (SNA) and longitudinal survey data, we analyzed how 31 distributed learners developed collaborative learning social networks, when they had work together on the design of aerospace systems using online collaboration tools. The results showed that both individual and structural factors (i.e., communication styles and a pre-existing friendship network) significantly affected the way the learners developed collaborative learning social networks. More specifically, learners who possessed high willingness to communicate (WTC) or occupied initially peripheral network positions were more likely to explore new network linkages. We also found that the resultant social network properties significantly influenced learners’ performance to the extent that central actors in the emergent collaborative social network tended to get higher final grades. The study suggests that communication and social networks should be central elements in a distributed learning environment. We also propose that the addition of personality theory (operationalized here as communication styles) to structural analysis (SNA) contributes to an enhanced picture of how distributed learners build their social and intellectual capital in the context of CSCL.     

The role of presence awareness in organizational communication: An exploratory field experiment

Millions of adults currently use instant messaging (IM) in the workplace, and yet there is very little research examining how use and perceptions of this new medium affect intra-organizational communication. While one of the characteristics of instant messaging is the ability to exchange real-time communication, what truly distinguishes instant messaging from other widely adopted forms of mediated communication is the integration of presence technology, which allows parties to detect if others are online and available to communicate. In this paper, we propose a theory of productivity benefits of presence-aware communication technology, building upon past research. Based on this model, we use a quasi-experimental longitudinal research design to test how providing instant messaging to selected workgroups at a Fortune 500 company impacts employees' attitudes and work behavior.

Results suggest that IM use had a positive effect on improving productivity with participants citing reductions in voice mail and phone tag, improvements to how easy it was to see if colleagues were online and available to communicate as well as increased productivity served by back-channel communications conducted via IM. Results and future research directions are discussed.     

The Impact of Technology Availability and Structural Guidance on Group Development in Workgroups Using Computer-Mediated Communication

This article examines how technology and structural guidance influence the development of workgroups using computer-mediated communication (CMC). The results of two experiments support the notion that CMC workgroups develop over time in a similar manner to face-to-face groups. Technology availability had minimal, fleeting effects on group development. Structural guidance had a more pronounced effect, increasing feelings of belonging and goal commitment in newly formed groups, but lowering feelings of trust in maturing groups.     

Performance improvement of web caching in Web 2.0 via knowledge discovery

Web 2.0 systems are more unpredictable and customizable than traditional web applications. This causes that performance techniques, such as web caching, limit their improvements. Our study was based on the hypotheses that the use of web caching in Web 2.0 applications, particularly in content aggregation systems, can be improved by adapting the content fragment designs. We proposed to base this adaptation on the analysis of the characterization parameters of the content elements and on the creation of a classification algorithm. This algorithm was deployed with decision trees, created in an off-line knowledge discovery process. We also defined a framework to create and adapt fragments of the web documents to reduce the user-perceived latency in web caches. The experiment results showed that our solution had a remarkable reduction in the user-perceived latency even losses in the cache hit ratios and in the overhead generated on the system, in comparison with other web cache schemes.     

组通信系统中组成员关系服务的设计和实现

在组通信系统中,成员关系的维护是一个非常重要的模块,它保证消息的次序传递和虚同步。为了使一个组中节点的数目易于扩充,采用多播树的层次结构来组织节点;当成员关系发生变化时采用一种一致性算法使得视图达到一致。在此基础上设计和实现了一个有效的组成员关系服务模块。