title: Unfolding large-scale online collaborative human dynamics.
abstract: Large-scale interacting human activities underlie all social and economic phenomena, but quantitative understanding of regular patterns and mechanism is very challenging and still rare. Self-organized online collaborative activities with a precise record of event timing provide unprecedented opportunity. Our empirical analysis of the history of millions of updates in Wikipedia shows a universal double-power-law distribution of time intervals between consecutive updates of an article. We then propose a generic model to unfold collaborative human activities into three modules: (i) individual behavior characterized by Poissonian initiation of an action, (ii) human interaction captured by a cascading response to previous actions with a power-law waiting time, and (iii) population growth due to the increasing number of interacting individuals. This unfolding allows us to obtain an analytical formula that is fully supported by the universal patterns in empirical data. Our modeling approaches reveal "simplicity" beyond complex interacting human activities.
authors.affiliation: CompleX Lab, Web Sciences Center, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China.|Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong.|Centre for Nonlinear Studies, Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong.|The Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Zha
authors.affiliation: CompleX Lab, Web Sciences Center, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China; zhutou@ustc.edu cszhou@hkbu.edu.hk.|Beijing Computational Science Research Center, Beijing 100084, People's Republic of China.|Big Data Research Center, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong; zhutou@ustc.edu cszhou@hkbu.edu.hk.|Centre for Nonlinear Studies, Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong.|The Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong.|Beijing Computational Science Research Center, Beijing 100084, People's Republic of China.|Research Centre, Hong Kong Baptist University Institute of Research and Continuing Education, Shenzhen 518000, China.
authors.forename: Changsong
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000465:Algorithms; D001519:Behavior; D003299:Cooperative Behavior; D003625:Data Collection; D055866:Earthquakes; D034742:Electronic Mail; D006802:Human Activities; D006801:Humans; D020407:Internet; D015233:Models, Statistical; D016012:Poisson Distribution; D011157:Population Dynamics; D011158:Population Growth; D012919:Social Behavior; D012984:Software; D013223:Statistics as Topic; D013997:Time Factors
keywords: double power law; human dynamics; multibranching; online collaboration