Incentive and culture: shaping information and social dynamics in online information sharing systems

The most revolutionary power of the Internet lies in the way it changes people's collaborative work, aggregating social knowledge at an ever-increasing speed. This trend has been manifested in a variety of social information sharing and augmenting systems, such as Wikipedia, Question-and-Answer (Q&A) forums, and crowdsourcing websites. Understanding the information and social dynamics involved in these systems is crucial to improve their design and truly harness their power. This dissertation is devoted to investigating how two important factors, incentive and culture, significantly and interactively shaped users' information and social behavior in the information-sharing websites I studied. This dissertation is organized by four interlinked studies, which address incentive design in online information sharing systems from four perspectives: how users learn and adapt their behavior to an incentive design dynamically; how users' adaptation dynamics contribute to a positive feedback mechanism that sustains the community; how culture deeply influences information and social dynamics, even given with very similar virtual point incentive designs and system platforms; and how incentive design can interact with a particular community structure and cultural context in a very comprehensive and complex way, and how the interaction can lead to a co-evolution process between the users and the way users perceive and use the incentive design.