Talking to a System and Talking to a Human: A study from a Speech-to-Speech, Machine Translation mediated Map Task

This study focuses on the properties of Human-to-Human (H2H) communication in spontaneous dialogues in two different settings. Direct H2H dialogues are compared to the ones that are mediated by a Speech-to-Speech machine translation system. For the analysis, dialogues from the HCRC Map Task Corpus, for direct H2H conversations, and dialogues from the ILMT-s2s Corpus, for computer mediated conversations, were used. In the conversations speakers take the roles of information giver and follower and all the utterances are labelled as instructions, questions or statement, etc. While direct H2H communication enables speakers also to benefit from non-verbal acts, gestures and facial expressions, machine mediated conversation is more complex for the interlocutors. Due to errors made by speech recognition system, speakers adapt their speaking style and also apply repair strategies in order to accomplish the tasks successfully. Comparing the two corpora showed that in the case of computer mediated communication the utterances of the speakers contained less words than in the case of direct H2H interaction where utterances were longer. Also, different word count was found depending on the role of the speaker as well as on the type of the utterance.