Information Relaxation is Ultradiffusive

Huberman, Bernardo ; Ghosh, Rumi

HP Development Company

关键词: social media;    information flow;    ultrametricity;   

RP-ID  :  HPL-2012-249

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

We investigate how the overall response to a piece of information evolves and relaxes as a function of time in social networks like Reddit, Digg and Youtube. This response or popularity is measured in terms of the number of votes/comments that the story (or article) accrued over time. We find that the temporal evolution of popularity can be described by a universal function whose parameters depend upon the system under consideration. Unlike most previous studies, which empirically investigated the dynamics of voting behavior, we also give a theoretical interpretation of the observed behavior using ultradiffusion. Whether it is the inter arrival time between two consecutive votes on a story on Reddit or the comments on a video on Youtube, there is always a hierarchy of time scales in information propagation. One vote/comment might occur almost simultaneously with the previous, whereas another vote/comment might occur hours after the preceding one. This hierarchy of time scales leads us to believe that the dynamical response of users to information is ultradiffusive in nature. We show that a ultradiffusion based stochastic process can be used to rationalize the observed temporal evolution. We demonstrate that the results predicted by simulating the ultradiffusion process are in close correspondence to the actual observations.