title: Collective phenomena and non-finite state computation in a human social system.
abstract: We investigate the computational structure of a paradigmatic example of distributed social interaction: that of the open-source Wikipedia community. We examine the statistical properties of its cooperative behavior, and perform model selection to determine whether this aspect of the system can be described by a finite-state process, or whether reference to an effectively unbounded resource allows for a more parsimonious description. We find strong evidence, in a majority of the most-edited pages, in favor of a collective-state model, where the probability of a "revert" action declines as the square root of the number of non-revert actions seen since the last revert. We provide evidence that the emergence of this social counter is driven by collective interaction effects, rather than properties of individual users.
authors.affiliation: Santa Fe Institute, Santa Fe, New Mexico, United States of America ; School of Informatics and Computing, Indiana University, Bloomington, Idiana, United States of America.
authors.forename: Simon
authors.initials: S
authors.lastname: DeDeo
mesh_terms: D003299:Cooperative Behavior; D006801:Humans; D020407:Internet; D008962:Models, Theoretical; D012919:Social Behavior