Use of demonstrative words between speaker and hearer in virtual space

To realize interactive robots that watch for humans, it is necessary for robots to keep distance adequately from humans. The robot must keep away from the person to monitor for avoiding unnecessary interference, while the robot must approach to the person for active communication or supportive actions. Thus, in addition to that distance between the robot and the person must be properly controlled, the human intention of either “I act, without your help” or “You act, help me” must be specified. Demonstrative words such as “this” and “that” may be used as one way to control this distance information and understand human desire for support. We investigated the relationship between distance and demonstrative words when a speaker utters demonstrative words to a hearer in cooperative carrying task using virtual space. We used 3 corpus of speech to extract demonstrative words, then we calculated the distance between the speaker´s and the hearer´s position to the object to be moved. Results indicated 1) Demonstrative “Kore (This)” was used when the speaker´s position was near to the objects. 2) Demonstrative “Sore (That-proximal)” was used when the hearer´s position was near to the objects. 3) Demonstrative “Are (That-distal)” was not observed. It was also suggested that the aspect of distance (proximal/distal) was not the key factor of the use of Japanese demonstratives in virtual space. “Kore” was often used for objects that the speaker oneself wanted to act on, while “Sore” was often used for objects that the speaker wanted the other person (who was close to the object) act on. Whether the speaker himself wanted to act or he wanted the hearer act was the key factor of the use of these demonstratives