In this lecture, we will discuss a collaborative project among the University of Tsukuba, Intel Corporation, and Tsukuba City Hall that established a social networking service (SNS) community (Facebook community: Tsukuba Civic Activities Cyber-Square) aiming to strengthen cooperation between a local government and civil society. The project faced a problem of periodically observing a decline in Facebook community activity, and we will introduce the data science research methods that were used to analyze and clarify the problem.