Abstract: A legged mobile robot realizes a motion language by a time-series change in an actuator angle or a motion pattern using the four limbs and the trunk. A motion language which includes, for example, a motion pattern which is an approximation of the contour/shape of a character is used, so that even a robot or a human being which does not possess the same motion language database can determine the meaning and character which is indicated by each motion pattern as a result of visually recognizing and interpreting the contour/form which is indicated by each motion pattern. For example, a robot which has stepped into a dangerous working area can give a message concerning, for example, the condition of the working area to an observer at a remote location without using any data communications means. The legged mobile robot communicates by moving the limbs and/or the trunk.

Abstract: A conversation processing apparatus and method determines whether to change the topic. If the determination is affirmative, the degree of association between a present topic being discussed and a candidate topic stored in a memory is computed with reference to a degree of association table. Based on the computation result, a topic with the highest degree of association is selected as a subsequent topic. The topic is changed from the present topic to the subsequent topic. The degree of association table used to select the subsequent topic is updated.