Static and Dynamic Structure Characteristics of a Trust Network and Formation of User Trust in an Online Society

This study investigated the characteristics and formation of the online social trust network of Epinions.com, a general consumer review site. An analysis of the static structure of this social trust network revealed a high clustering coefficient, short average path length, and power-law degree distribution;it is therefore a small-world and scale-free trust network. The dynamic evolutionary characteristics of the online social network (OSN) were also examined. The results showed that the scale of the network followed a sigmoidal curve;the average degree of the network was nonconstant and changed into a bell-shaped distribution;the density of the network decreased and subsequently stabilized;and user trust diffusion in the network conformed to the Bass model. Finally, the formation of trust within the network was researched at the overall network (macro) and individual user (micro) levels. Compared with their accumulated contribution and reputation, user activeness had a larger effect on trust formation in OSNs, indicating a “diminishing returns” phenomenon. This phenomenon contrasts with the Matthew effect (i.e. , the more reputation a person has, the more likely he or she is to be trusted) in real-world social networks.

Social effects of topic propagation on Weibo

Weibo,China’s largest microblogging platform,has become one of the key information-sharing platforms in modern society.This study examines topic propagation in relation to microblogging from the perspective of the“peer effect.”Using data of hot topics from Weibo,we analyze how the social effect and propagation pathway influence the topic propagation process.We propose a spatial and temporal heterogeneity diffusion model that includes endogenous and exogenous social effects and is based on but different from the Bass diffusion model.We find that most propagation pathways end after a single level of propagation.The endogenous social effect in microblogs primarily influences the inflow of topics.Such endogenous social effect,combined with the multiplier effect,motivates most users to share a microblog topic in a short period of time.The exogenous social effect primarily influences the outflow of topics,and therefore,the microblog topics of a small number of popular users’account for most of the share volume.Our results are robust to potential serial correlation,reflection problem,and potential self-selection due to user status.The findings reveal that group characteristics affect individuals’behaviors and choices in relation to the topic propagation process on microblogging platforms.The use of a spatial and temporal heterogeneity diffusion model and the robustness of the analysis process provide new information for scholars in this field.