“…The research can be tracked back to the GRUNDY system (Rich, 1979) which categorizes users in terms of hand-crafted sets of user properties for book recommendation. Other systems have focused on different aspects of users, e.g., the expertise level of the user in a specific domain (Chin, 1986;Sleeman, 1985;Paris, 1987;Hovy, 1987), the user's intent and plan (Allen and Perrault, 1980;Carberry, 1983;Litman, 1986;Moore and Paris, 1992), and the user's personality (Mairesse and Walker, 2006;DeVault et al, 2014;Fung et al, 2016;. User modeling has also been employed for personalized topic suggestion in recent Alexa Prize socialbots, using a pre-defined mapping between personality types and topics , or a conditional random field sequence model with hand-crafted user and context features (Ahmadvand et al, 2018).…”