中文摘要：

大数据时代，移动虚拟社区是人们信息传播和获取的重要途径，已成为理论与实践研究的热点．文章围绕在没有收益回报保证的前提下，为何知识贡献者也愿意花费时间和精力将自己的知识贡献给他人的问题，为全面分析和解释其影响因素，论述了社会认知理论的优越性，并通过实证研究证明个人结果期望是重要的影响因素，并在环境因素与行为之间起中介效应。与以往研究自我效能的中介作用有所不同，更符合文章的研究情景，丰富了对该领域的研究。

英文摘要：

In the age of big data, mobile virtual community is an important way for people to spread and obtain information, which has become a hot topic of the theoretical and practical studies. This paper discusses around the question that under the prem- ise of no guarantee for income return, why knowledge contributors are willing to spend time and effort contributing their knowledge to others. In order to comprehensively analyze and interpret the influencing factors, the paper proves the superiority of social cogni- tive theory and demonstrates that individual outcome expectation is an important factor with mediating effect between environmental factors and individual behaviors. Different from previous researches which study the intermediary effect of self-efficacy, the paper is closer to the research context and enriches the researches in the field.