Heterogenous Human Dynamics in Intra and Inter-day Time Scale

In this paper, we study two large data sets containing the information of two different human behaviors: blog-posting and wiki-revising. In both cases, the interevent time distributions decay as power-laws at both individual and population level. As different from previous studies, we put emphasis on time scales and obtain heterogeneous decay exponents in intra- and inter-day range for the same dataset. Moreover, we observe opposite trend of exponents in relation to individual $Activity$. Further investigations show that the presence of intra-day activities mask the correlation between consecutive inter-day activities and lead to an underestimate of $Memory$, which explain the contradicting results in recent empirical studies. Removal of data in intra-day range reveals the high values of $Memory$ and lead us to convergent results between wiki-revising and blog-posting.