Additionally, <cite>Liu et al. (2017)</cite> explored the use of context information concerning speaker changes and from the surrounding segments. The first was provided as a flag and concatenated to the segment representation. Concerning the latter, <cite>they explored</cite> the use of discourse models, as well as of approaches that concatenated the context information directly to the segment representation. <cite>The discourse models</cite> transform the model into a hierarchical one by generating a sequence of dialog act classifications from the sequence of segment representations.