Research in other domains (Litman et al., 2001;Batliner et al., 2003) has shown that features representing the di-alogue context can sometimes improve the accuracy of predicting negative user states, compared to the use of features computed from only the turn to be predicted.
we investigated the impact of supplementing our turn-level features in Figure 2 with the features in Figure 4, representing local and global 10 aspects of the prior dialogue, respectively.