“…Dialogue Systems are categorized into chit-chat (Vinyals and Le, 2015;Serban et al, 2016) and task-oriented (Williams and Young, 2007;Young et al, 2013); in this paper we focus on the latter. Task-oriented dialogue systems are further classified into: modularized (Levin et al, 2000;Hori et al, 2009;Lee et al, 2009), retrieval (Henderson et al, 2019; end-to-end (Bordes and Weston, 2017;Eric et al, 2017a;Eric and Manning, 2017;Madotto et al, 2018;Madotto et al, 2020a;Neelakantan et al, 2019;He et al, 2020) and hybrid (Shu et al, 2018;Lei et al, 2018;Zhang et al, 2019a;Mehri et al, 2019;Peng et al, 2020a;Ham et al, 2020;Hosseini-Asl et al, 2020;Le et al, 2020;Lin et al, 2020). To the best of our knowledge, these methods use either DST/S-ACT annotations, template responses, or all/partial KB as the input to the model, where instead we only use the dialogue history.…”