Information Relaxation is Ultradiffusive

TL;DR

This paper demonstrates that the temporal evolution of information popularity on social networks follows a universal pattern explained by ultradiffusion, revealing a hierarchy of time scales in user responses.

Contribution

It introduces a theoretical framework using ultradiffusion to interpret the universal dynamics of information spread and response times in social media platforms.

Findings

Popularity evolution follows a universal function with system-dependent parameters.

Hierarchical time scales govern the timing of votes and comments.

Ultradiffusion models can rationalize the observed temporal dynamics.

Abstract

We investigate how the overall response to a piece of information (a story or an article) 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 shared 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.