Blinking light patterns as artificial subtle expressions in human-robot speech interaction

Users' impressions of blinking light expressions used as artificial subtle expressions have been investigated. In a preliminary experiment, thirteen blinking patterns were used for investigating participants' impressions of their agreeableness. The highest and lowest valued blinking patterns were identified and used for a speech interaction experiment. In this experiment, 52 participants tried to reserve hotel rooms with a spoken dialogue system coupled with an interface robot using a blinking light expression. A sine wave, a random wave, a rectangular wave, and a no-blinking condition were used as artificial subtle expressions to express a robot's internal state of “processing” or “recognizing”. The results of a questionnaire showed the conditions did not significantly differ in terms of agreeableness, but the sine wave and the rectangular wave were evaluated as “more useful” than the no-blinking condition. Results of factor analyses suggested that the rectangular wave provides a comfortable impression of the dialogue.