由於網際網路的蓬勃發展，帶動了虛擬社群的快速成長，使用者對於虛擬社群的需求，不再只是侷限於聊天、交友；而是將虛擬社群當作知識分享的平台，與他人進行知識交流，衍生出以知識為主題的專業虛擬社群。 本研究整合個人層級之社會資本理論與個人內在、外在動機，建構出研究模型，檢驗專業虛擬社群成員在何種動機的驅使下，願意將知識分享給他人，了解為什麼有好心陌生人的存在。社會資本構面，包含網絡密度、共同理解、信任及利分享規範；個人外在動機構面，包含名譽、互惠、社群結果預期；個人內在動機構面，包含樂於幫助他人、知識自我效能、承諾。 本研究針對JavaWorld@TW專業虛擬社群蒐集到207份有效問卷(全數樣本)，包含53位分享者、154位潛水者，提供本研究模型、假說之檢驗。研究發現在全數樣本、潛水者模型中，「信任」、「利分享規範」為「共同理解」與「知識分享態度」的中介變數，在專業虛擬社群與成員之間扮演的中介角色。「樂於幫助他人」、「承諾」、「社群結果預期」能顯著地對分享者的知識分享態度造成正面影響；而潛水者則主要受到「互惠」、「社群結果預期」的影響。樣本資料顯示分享者和潛水者之間的內在、外在動機存在差異。 Due to the rapid development of the Internet, virtual communities are growing at an unprecedented rate. Users’ needs for a virtual community not only limit to chat or make friends, but also regard it as a knowledge exchange platform to communicate with others. Nowadays, there are a variety of knowledge-based professional virtual communities. This paper proposes an integrated model by intergrating the Social Capital Theory and intrinsic and extrinsic motivations of individuals to investigate motivations behind people's knowledge sharing in professional virtual communities, and understanding why the kindness of strangers exist. Data collected from 207 users of the JavaWorld@TW professional virtual community which include 53 contributors and 154 lurkers provide investigation for the proposed model and hypotheses. Results suggest that trust and pro-sharing norms mediate between shared understanding and knowledge sharing attitude in the model of all samples and lurkers. Besides, results show that enjoyment helping others, commitment, and community-related outcome expectations enhance contributors’ attitudes toward knowledge sharing. Reciprocity and community-related outcome expectations will influence lurkers’ knowledge sharing. It is found from our samples that extrinsic and intrinsic motivations of contributors are different from those of lurkers.
