“…Here, a SDS could react 90 by adapting the dialog strategy when critical situations are 91 automatically detected, cf. Langkilde et al (1999), ?, 92 Walker et al (2002), Hastie et al (2002), Levin and 93 Pieraccini (2006), Herm et al (2008), Schmitt et al 94 (2008), Zgorzelski et al (2010), Schmitt et al (2010c), 95 Ultes et al (2011Ultes et al ( , 2012Ultes et al ( , 2014a. Another option would 96 be the escalation to a live agent who finishes the task jointly 97 with the user.…”