Finding Optimal Policies for Online Communities with CoSiMo

The rapidly increasing popularity of Web 2.0 online com- munities originates in the ease of collaborative content cre- ation and its sharing. As a result, more community members actively participate in the community and its data growth rates are continuously increasing. This poses the challenge for community platform operators on ecient administra- tion and moderation to ensure the quality of content and to prevent violations of laws (e.g. copyright, privacy, illegal content) and community rules. Involvement of employed administrators who read and ap- prove every piece of user-generated content is clearly the safest way of quality assurance. Since this is a time con- suming task it does not scale up with Web 2.0 dimensions. So administrative functions are delegated to members of the community, the moderators. The strategy for choos- ing trustworthy moderators in big anonymous communities is specied in policies based on user reputation that is mea- sured in bonus points. The proper balancing between community self-management and administration is crucial for the quality, attractiveness, and scalability of the entire community. Therefore under- standing the mutual inuences between community actors, reputation systems and platform policies that employ user reputation is crucial to ensure the overall quality, user ac- ceptance, and success of the entire online community. Our objective is to predict the behavior in an online com- munity for dierent policies, which may result in dierent overall quality of the community content. For this purpose we present our community analysis framework CoSiMo (an acronym for Community Simulation and Modeling), which employs the model-based approach for predicting the impact of policies on community dynamics and health. Through systematic variation of simulated quality assurance mech- anisms we show that our model plausibly captures the in- uence of policies to content quality and can be therefore exploited for optimization of real online communities.