Emergence of Power Laws in Online Communities: The Role of Social Mechanisms and Preferential Attachment

As summarized in Table A1, this appendix provides a detailed description of the research method used to test the proposed hypotheses. The first major step was to collect observational and trace data from online communities. The observational data supported creation of a descriptive model of online community formation. The trace data encompasses the first 12 to 15 months of communication in 28 online communities that were randomly selected into a model specification sample and a model testing sample. In the next major step, the descriptive model was turned into a formal model of online community formation and then implemented in R. The first 12 to 15 months of data from the online communities in the model specification sample provide key simulation parameters (e.g., participant arrival and departure rates).