How Quickly Should Communication Robots Respond?

Abstract

This paper reports a study about system response time (SRT) in communication robots that utilize human-like social features, such as anthropomorphic appearance and conversation in natural language. Our research purpose established a design guideline for SRT in communication robots. The first experiment observed user preferences toward different SRTs in interaction with a robot. In other existing user interfaces, faster response is usually preferred. In contrast, our experimental result indicated that user preference for SRT in a communication robot is highest at one second, and user preference ratings level off at two seconds. However, a robot cannot always respond in such a short time as one or two seconds. Thus, the important question is "What should a robot do if it cannot respond quickly enough?" The second experiment tested the effectiveness of a conversational filler: behavior to notify listeners that the robot is going to respond. We used the same strategy in a communication robot to shadow system response time. Our results indicated that using a conversational filler by the robot moderated the user's impression toward a long SRT. Put it all together, we obtained a) users' impressions toward the robot are unchanged until one second SRT, b) the robot should react within two seconds SRT, and c) use of conversational fillers are effective to let the users to wait from these two experiments.

Cognitive aspects of communicating information with conversational fillers in Slovak

“…Moreover, although some applications using CF in speech generation exist, e.g. [20] showed that a turn-initial CF produced by a robot significantly improved the user's impression of longer response times, the design of cognitive artificial agents, equipped with limited functionality in recognizing and producing the form-function relationship associated with CFs, still represents a challenging goal. In this paper we attempt to pursue these overall goals by reporting on the form-function relationship of Slovak conversational fillers uh and mm in task-oriented dyadic spontaneous human-human conversations.…”

Supervisory control of multiple social robots for navigation

“…A previous study [20] revealed that individual people have preferable ranges of speed while walking together with a robot. Studies of conversational interactions [12,17,18] have found that the use of speech by robots during degraded states can effectively reduce customer frustration. By combining those ideas, our solution is to choose an acceptable slow speed, and to use speech to increase people's tolerance toward that slow speed.…”

“…For example, if the operator's attention is focused too much on a single robot, then the other robots may be overlooked and operating in degraded states for a long time, which may eventually lead robots to dangerous states or decrease the total performance of the robot team. For robots conducting social interactions with people, degraded responses by the robots can cause frustration and a negative impression toward the robots [12].…”

An affective guide robot in a shopping mall

“…However, since users might feel uncomfortable during slow responses or long pauses, robot response time is critical. To solve such problems, we implemented a conversational filler to buy time [29]. When the operator needs a few seconds, he/she executes a conversational filler behavior to notify listeners that the robot is going to respond soon.…”