Redirecting player speech : Lexical entrainment to challenging words in human–computer dialogue

Sammanfattning: In a well-documented approach to dealing with the immense diversity of human language, the words that a dialogue system can understand are embedded in its output speech, causing human speakers to spontaneously adopt words familiar to the system—a process known as lexical entrainment. In previous studies, however, the tasks have been simple and the words suggested by the computer close synonyms to the ones that the participant originally used. This Wizard of Oz–study attempted to discern the confinements of lexical entrainment by urging participants to swap to a more difficult set of words, in a more complex context. Remote participants were ushered by an agent co-player to switch from using cardinal directions to using left/right, and vice versa, when describing the position of countries in a dialogue-based game. The corpus consisted of 32 dialogues. Results suggested that, even in the slightly more challenging and unpredictable context of the geography game, people accommodate the words suggested by the computer. Contrary to expectations, the group subject to the swap that was considered to be the most difficult demonstrated the greatest level of entrainment. Based on the results, it would seem that entrainment depends not so much on levels of difficulty of the substitute words, but on what makes sense to speakers in a specific context. This ties in with the idea of conceptual pacts. People will still entrain in slightly challenging situations, but attaining high levels of entrainment in human–computer dialogue requires context-appropriate lexical choice.