Lognormal Distribution of BBS Articles and its Social and Generative Mechanism

The objective of this paper is to understand an aspect of human social interaction in public bulletin board systems (BBSs). We try to answer the question of why and how a long and hot chain of articles often emerges in BBSs. This paper presents the following three contributions. (1) empirical results: we measured and analyzed actual BBS logs, and found that the number of articles submitted by each individual in an article chain follows a lognormal distribution. (2) model: to investigate why the distribution emerges through individual activities, we developed a simple model of voluntary submission activity for each individual. With only this simple mechanism, the lognormal distribution shown in actual data is reproduced. (3) analytical solution: we showed that the model generates a lognormal distribution when the number of members in a BBS community is constant, and the individuals in a community are homogeneous