“…Event causality relations have been used in why-question answering systems to focus on causalities between questions and answers (Oh et al, 2013(Oh et al, , 2016(Oh et al, , 2017. It is also reported that a conversational model using event causality relations can generate diverse and coherent responses (Fujita et al, 2011). However, the relation between dialogue continuity and the coherency of system responses is still an underlying problem.…”