We were developed system that does the prompting of communications by arranging “●”prompter at random in the message box, and verified effectiveness in online communications that use computer. In this paper, We analyzed the problem structure in “●” use from system user's interview data by using the grounded theory approach, and did modeling in “●” use process. As a result, the effect of “●” becomes clear, and the utility of the system was verified, it reports.