复制式协同设计环境中基于地址空间转换的关联操作一致性维护策略研究

在复制式架构的二维协同设计系统中,地址空间转换算法可用来实现共享文档的一致性维护.然而,该算法无法直接处理关联操作,而是采用先分解后执行的方式进行,在操作分解执行过程中,远程并发操作的存在可能会导致关联操作所依赖的实体属性发生改变,从而使关联操作丢失被参照实体与参照实体之间的关联关系,导致其语义一致性无法维持.本文通过在地址空间转换策略的内部线性地址空间上添加原操作及本地操作历史序列,修正本地操作广播及远程操作接收过程以维持各分解操作的关联关系,并引入Retrace-Undo-VT-Redo-Retrace控制过程,实现对关联操作语义信息的分布式维持.本文最后通过实例分析展示了整个策略的工作过程.     

Providing effective feedback, monitoring and evaluation to on-line collaborative learning discussions

Learning and knowledge building have become critical competences for people in the knowledge society era. In this paper, we propose a sociolinguistic dialogue model for understanding how learning evolves and how cognitive process is constructed in on-line discussions. The knowledge extracted from this model is used to assess participation behavior, knowledge building and performance. The ultimate purpose is to provide effective feedback, evaluation and monitoring to the discussion process. Seven hundred students from the Open University of Catalonia in Spain participated in this study. Results showed that learning and knowledge building may be greatly enhanced by presenting selected knowledge to learners as for their particular skills exhibited during interaction. In addition, this valuable provision of information is used as a meta cognitive tool for tutors and moderators for monitoring and evaluating the discussion process more conveniently. This contribution presents our conceptual model for interaction management as well as key design guidelines and evaluation results. Implications of this study are remarked and further research directions are proposed.     

Effects of face-to-face versus chat communication on performance in a collaborative inquiry modeling task

In many contemporary collaborative inquiry learning environments, chat is being used as a means for communication. Still, it remains an open issue whether chat communication is an appropriate means to support the deep reasoning process students need to perform in such environments. Purpose of the present study was to compare the impact of chat versus face-to-face communication on performance within a collaborative computer-supported modeling task. 44 Students from 11th-grade pre-university education, working in dyads, were observed during modeling. Dyads communicated either face-to-face or through a chat tool. Students’ reasoning during modeling was assessed by analyzing verbal protocols. In addition, we assessed the quality of student-built models. Results show that while model quality scores did not differ across both conditions, students communicating through chat compressed their interactions resulting in less time spent on surface reasoning, whereas students who communicated face-to-face spent significantly more time on surface reasoning.     

Investigating factors that influence social presence and learning outcomes in distance higher education

There are many factors that influence distance learning especially in higher education where collaborative and communicative discourse is necessary for pursuing knowledge. Social presence, among other factors, is an important concept to be facilitated, developed and sustained in distance higher education as it promotes and supports discourse based learning. This study examines the relationship among demographic and other variables, social presence and learning satisfaction. Results showed demographic variables, such as gender, online learning experience and work status were not significant factors in terms of influencing on either social presence or learning satisfaction. While media integration and instructor’s quality teaching were significant predictors of both social presence and learning satisfaction, interactivity among participants was a predictor of social presence but not of learning satisfaction. Along with the study findings, some implications were discussed for online learning practitioners in higher education setting.     

Group awareness tools: It’s what you do with it that matters

This study examined the effect of using a group awareness tool on online collaboration. Furthermore, we examined whether the effect of using a group awareness tool on online collaboration is mediated by group awareness (i.e., students’ awareness of their group members’ levels of participation). To answer these questions, we determined how often and how long 107 secondary education students used the Participation-tool (PT), a group awareness tool designed to visualize group members’ relative contribution to the online collaborative process. Our analyses show that duration of PT use (how long students displayed the tool on their screens) significantly predicted group members’ participation in the online dialogue, their participation when writing collaborative texts, equality of participation within the group, and coordination and regulation of activities in the relational space (i.e., discussing the collaboration process with group members). No effect of using the PT on group performance was found. Mediation analyses showed that the effect of using the PT is only partially mediated by group awareness: an indirect effect of using the PT, via enhanced awareness of participation, on student participation during chat discussions and the collaborative writing process was found.     

Design and evaluation of a collaborative learning environment

Collaboration becomes an essential competency in the current knowledge society. In this study, a collaborative learning environment was designed to facilitate students in group collaboration. Instructional support strategies of friendship and meaningful learning tasks were applied to promote collaboration. Scaffolding strategies such as writing progress reports and developing product versions were used to coordinate and monitor the collaborative learning environment. In addition, the online file sharing tool DriveHQ was used to facilitate collaboration. Four classes of students used the learning environment to complete their final project in pairs. Results showed friendship and meaningful learning tasks helped to promote individual accountability and positive interdependence, and the use of progress reports and product versions was useful for coordinating and monitoring the learning process. However, additional strategies might be needed for more effective collaboration to take place. Issues involved in this study are discussed.     

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.     

The impact of media on collaborative learning in virtual settings: The perspective of social construction

This study examines an alternative function of information sharing – social construction of meaning. Drawing on social construction, social interaction, and task closure theories, we explored the influence of both the media environment in which students are situated and the medium that group members choose to communicate with one another on the intricate relationships among breadth of information sharing, depth of information sharing, and performance of computer-supported collaborative learning (CSCL). A total of 126 students participated in the experiment – including 63 students (15 groups of four students and one group of three students) in the control and experimental groups respectively. Our findings show that most of the proposed hypotheses are supported. Intersubjective interpretation underlies groups information sharing and plays a key role in student learning performance. Evidence shows that when facing a relatively complex task in multimedia environments, students who choose to utilize a medium lower in social presence (i.e., electronic information sharing) are more likely to achieve task closure than a medium higher in social presence (i.e., verbal information sharing). This in turn leads to higher learning performance. The implications for both theory and pedagogy are also discussed.     

Developing Web literacy in collaborative inquiry activities

Although many children are technically skilled in using the Web, their competences to use it in a critical and meaningful way are usually less well developed. In this article, we report on a multiple case study focusing on the possibilities and limitations of collaborative inquiry activities as an appropriate context to acquire Web literacy skills in primary education. Four 5th grade school teachers and their students worked with collaborative inquiry activities on the subject of ‘healthy food’. The project was aimed at both the development of Web literacy skills and content knowledge building. Data from a variety of sources were collected: videotaped and written lesson observations, interviews with teachers and students, teacher diaries, student questionnaires, and student assignments. The teachers appeared to be able to carry out the program to varying degrees. Contextual factors that influenced the realization of the project’s goals and results were the adequacy of the research questions formulated by students, students’ inquiry skills, and the teachers’ teaching styles. Students’ learning results show that it is possible to teach Web literacy skills in the context of collaborative inquiry activities. All classes show knowledge gain with regard to the subject healthy food and all classes but one show knowledge gain with regard to Web literacy skills. Although many students show adequate use of particular Web searching, reading and evaluating skills after the project, inconsistency, impulsiveness and impatience are also typical of their Web behaviour. In the context of collaborative inquiry activities teachers are challenged to deal with the paradox that they want their students to be active knowledge builders with help of the Web, whereas the Web seems to invite students to be more or less passive searchers.