The Research Of Social Network Structure Of The Virtual Learning Community

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.