【作者】 王陆；

【导师】 南国农； 杨改学；

【作者基本信息】 西北师范大学 ， 教育技术学， 2009， 博士

【摘要】 虚拟学习社区(Virtual Learning Communities,缩写为VLCs)既是一种基于网络而形成的学习型组织,也是一种由计算机、Internet网络和人所组成的人-机复杂系统。虚拟学习社区中的成员对话是虚拟学习社区中有效学习的不可或缺的“生命血液”,对话所产生的互动使得成员之间建立起关系,而社区成员及其关系的集合就是虚拟学习社区的社会网络(Social Network)。虚拟学习社区中成员之间实际存在或者潜在的关系模式,即为虚拟学习社区的社会网络结构,它可以分为三个层次:宏观层次的整体网络结构、中观层次的内部子结构和微观层次的网络位置与网络角色。本论文以首师大虚拟学习社区中的两门在线课程作为研究对象,聚焦于探索虚拟学习社区中的社会互动对网络教育效果的影响。首先,从社会互动过程萃取出虚拟学习社区社会网络结构;其次,研究虚拟学习社区中的社会网络结构与网络教育效果的因果模型,即社会网络结构特性为自变量,网络教育效果为因变量。本研究的内容共包括四个部分:(1)探索发现虚拟学习社区社会网络结构和网络教育效果之间的因果模型,为建构虚拟学习社区的社会网络结构中层理论提供重要基础;(2)形式化表达由于虚拟学习社区中的社会互动所形成的不同层次的社会网络结构,使虚拟学习社区的研究从描述性研究转向分析性研究,综合运用定量资料与定性资料,为能够更深入地认识虚拟学习社区的本质,提供认识论与方法论层面上的支持;(3)研究虚拟学习社区社会网络结构的动态演变过程及特点,为有效构建虚拟学习社区提供理论指导;(4)从社会网络的视角,提出影响虚拟学习社区网络教育效果的结构因素,补充发展虚拟学习社区的教学指导策略,以进一步改善网络教育效果,提升虚拟学习社区的学习水平。本研究以作者在虚拟学习社区中担任主讲教师的两门在线课程为具体的研究切入点,在巴斯德象限研究范式的指导下,同时投入了认识与应用研究,综合运用了多种研究方法,经历了三个研究阶段:(1)预研究阶段,作者完成了为期一年的虚拟学习社区教学实践与数据收集;(2)数据分析与处理阶段,作者综合运用社会网络分析方法、统计分析方法、内容分析方法,以及关键事件回忆访谈法等多种研究方法,针对虚拟学习学习社区中的社会网络结构,进行了详细的结构分析与形式化表达,获得了虚拟学习社区宏观、中观和微观三个层次的社会网络结构数据;(3)理论模型构建阶段,作者运用中层型与经验概括型等理论建构的命题模式,以虚拟学习社区社会网络结构数据为基础,研究得出虚拟学习社区社会网络结构变量与网络教育效果之间的因果模型。本研究的研究结论主要有以下三个方面:(1)虚拟学习社区的社会网络结构特征从宏观层次上看,虚拟学习社区的社会网络结构是一个具有多通路、多层次、高互惠性和高连通性特点的结构复杂型网络,且具有显著的目标引导型的演变特征;共有九个对网络教育效果有显著影响的整体网络结构变量,即:密度、网络效率、互惠性、聚类系数、连通性、可达性、特征向量、点入度和点出度等。从中观层次上看,虚拟学习社区的社会网络结构是由许多凝聚子群连结而成的复杂网络,这些凝聚子群在其内部具有高互惠性和强连结的特点,但各子群之间只有弱连结联系;不同凝聚子群占据了网络中的不同位置,因而具有不同的关系模式和学习特征。从微观层次上看,行动者所处的网络位置决定了其在社会网络结构中的角色;例如:中心位置决定了中心位置上的核心人物,结构洞位置决定了该位置上的意见领袖,结构对等位置决定了结构对等角色,自同构对等位置决定了自同构对等的凝聚子群,规则对等位置决定了规则对等角色等。本研究发现,中心位置比其他网络位置对网络教育效果具有更大的影响。(2)社会网络结构与网络教育效果之间的因果关系本研究得出以虚拟学习社区社会网络结构为自变量,以网络教育效果为因变量的五个因果模型。第一个因果模型分析网络结构变量与平时成绩的关系,得出与后者相关的自变量共有7个,即:特征向量、点入度、点出度、核心度、网络有效大小、网络的可达性和网络密度等。其中特征向量、点入度和点出度等3个变量,也就是学习者的中心性对学习者的平时成绩影响最大。第二个因果模型分析网络结构变量与信息分享层知识建构的因果关系,得出与后者相关的自变量有8个,即:网络效率、连通性、可达性、特征向量、点入度、点出度、核心度和有效大小等。其中以学习者的中心性对信息分享层知识建构影响最大。第三个因果模型分析网络结构变量与深化认识层的知识建构的因果关系,得出与后者相关的自变量有5个,即:网络互惠性、可达性、点入度、核心度和有效大小等。其中点入度,即学习者声望对深化认识层知识建构影响最大。第四个因果模型分析网络结构变量与意义协商层的知识建构之间的因果关系,得出与后者相关的自变量有6个,即:网络互惠性、可达性、点入度、点出度、核心度和是否担任意见领袖等。其中点入度和点出度,即学习者的声望与中心性两个中心性指标对意义协商层知识建构的影响最大。第五个因果模型分析网络结构变量与学习者的社会存在感之间的因果关系,得出与后者相关的自变量有5个,即:聚类系数、可达性、特征向量、核心度和有效大小等。其中特征向量和核心度对社会存在感影响最大。(3)虚拟学习社区的教学实践策略本研究总结出5个虚拟学习社区的教学实践策略:第一,恰当控制虚拟学习社区在线课程的规模;第二,主动创建虚拟学习社区的社会网络;第三,掌握基于演变规律的学习活动设计;第四,有效提高行动者的中心性与声望;第五,注重培养意见领袖的学习领导力。更多还原

【Abstract】 Virtual Learning Communities(VLCs)are not only kinds of network based learning organization, but also the complex systems that consist of computers, Internet and people. The dialogue among the members of VLCs is the lifeblood of effective learning. The interaction generated by the dialogue establishes the relations among members. The social network of VLCs is the set of the members and their relationships in VLCs. In VLCs, the relationship model of the actual or potential existence can be defined as a social network structure that includes three levels. The top is the macro-level that is the global network structure of the social network. The middle is the meso-level that is the internal sub-structure or subgroups. The bottom is the micro-level that defines the network positions and network roles.This dissertation selects the two online courses in CNU VLCs as the research objects; focuses on exploring the effects of the social interaction on the network based education of VLCs. At first, it extracts the social network structure from the social interactions. Then, the author studies the cause models of VLCs between the social network structure and the effects of the network based education. The parameters of the former are the independent variables, while the later are the dependent variables.This research contains four aspects. One is to extract causal models of the social network structure and the effects of the network based education, which can support the Middle-range Theory of the social network structure of VLCs. The second aspect is to visualize the different levels of social network structure, which is derived from the social interactions in the VLCs. It makes the research of VLCs as the analytical study instead of the descriptive study. It synthesizes the quantitative data and qualitative data, provides the epistemology and methodology perspective for deeply understand the intrinsic property of VLCs. The third aspect is to study the dynamic evolutionary process and the characteristics of the social network structure of the VLCs. It provides theoretical guidance on construction VLCs effectively. The fourth aspect is to find the factors of the social network structure that affects the network based education of the VLCs from the social network perspective. It impels the development of VLCs instruction strategies, improves the network based education of VLCs, and enhances effects.The research is start from the relationship data from the two online courses which instructed by the author self in the CNU VLCs. The author puts into both the understanding research and applying research at the same time according to the Pasteur Quadrant Research Paradigm. The research synthesizes a variety of research methods, and has undergone three phases. The first is the pre-study phase, in which the author has completed a one-year teaching practice of the VLCs and data collection. The second is the data analysis and processing phase, in which the author analyzed and visualized the social network structure of the VLCs to obtain the data of the social network structure in macro-level, meso-level and micro-level by synthetic use of the Social Network Analysis (SNA) method, Statistical Analysis (SA) method, Content Analysis methods (CA) method, and Critical Event Recall (CER) method. The last phase is the theoretical-model construction. At this phase, the author uses the theoretically constructed propositional-schemes of the middle-range and experience-based model to extract the causal models of the social network structure and the effects of the network based education based on the data from the two online courses in the CNU VLCs.This research can deduce three achievements:(1) Obtains the characteristics of the social network structure of VLCsFrom a macro-level point of view, the social network structure of the VLCs is a complex network with properties of multi-channel, multi-level, high reciprocity and high connectivity. It significantly has a goal-directedness feature in its evolution. There are nine variables in the global social network structure that affect the effects of the network based education. They are the density, network efficiency, reciprocity, clustering coefficient, connectivity, accessibility, eigenvector centralization, in-degree and out-degree. From the meso-level point of view, the VLCs social network structure contains a number of cohesive subgroups, which are connected internally by the high-reciprocity and strong links among the parts of the subgroup while externally by the weak links among subgroups. Each cohesive subgroup occupies its own position in the social network, so that it leads to different model of relationship and learning characteristics. From the micro-level point of view, the network positions of the actors determines their roles in the social network structure, such as the central positions vs. the core actors, the structure hole positions vs. the opinion leaders, the structural equivalence positions vs. the roles of structural equivalence, the automorphic equivalence positions vs. the roles of automorphic equivalence, and the regular equivalence positions vs. the roles of regular equivalence. Furthermore, the research finds that the central positions impact the network based education more effectively than other positions do.(2) Achieves the causal relationships between the social network structure and the effects of the network based educationThis study is for examine how the variables of social network structure (as the independent variables) influence the effects of the network based education (as dependent variables). Five causal models have been conducted. The first model analyzes what variables influence the score of the formative evaluation. It concludes seven related variables namely the centralization, in-degree, out-degree, coreness, effective network size,accessibility and density. Among them, the eigenvector centralization, in-degree and out-degree are the most three significant factors to the score of the formative evaluation.The second model analyzes what variables influence the knowledge construction of information-sharing. It concludes eight related variables namely the network efficiency, connectivity, accessibility, eigenvector centralization, in-degree, out-degree, coreness and effective network size. Same as model one, the eigenvector centralization, in-degree and out-degree are the three most significant factors to the knowledge construction of information-sharing.The third model analyzes what variables influence the knowledge construction of deeply understanding. It concludes five related variables namely reciprocity, accessibility, in-degree, coreness and effective network size. The in-degree variable that means the prestige of the learner is the most significant factor to the knowledge construction of deeply understanding.The fourth model analyzes what variables influence the knowledge construction of meaningful consultations. It concludes six related variables namely reciprocity, accessibility, in-degree, out-degree, coreness and whether the opinion leaders. Among them, the variables of in-degree and out-degree that mean the prestige and the centrality are the two most significant factors to the knowledge construction of meaningful consultations.The fifth model analyzes what variables influence the sense of social presence. It concludes five related variables namely clustering coefficient, accessibility, eigenvector centralization, coreness and effective network size. Among them, the variables of eigenvector centralization and coreness are the two most significant factors to the sense of social presence.(3) Concludes the teaching practice strategy of VLCsThis study concludes five teaching practice strategies of VLCs. The first strategy is to control properly the size of online courses in VLCs. The second is to create initiatively a social network in VLCs. The third is to handle the design of learning activities that is based on the disciplinarian of the evolution of the social network structure. The fourth is to enhance effectively the centrality and prestige of actors. The fifth is to pay much attention to cultivating opinion leaders and their talents of learning leadership.更多还原