Similarities and Differences in Users’ Interaction with a Humanoid and a Pet Robot
Anja Austermann *1, Seiji Yamada *1,2

Kotaro Funakoshi, Mikio Nakano*1 The Graduate University for Advanced Studies (SOKENDAI)*2National Institute of Informatics
Tokyo, Japan{anja, seiji}@nii.ac.jp

Honda Research Institute Japan
Wako, Japan{funakoshi, nakano}@jp.honda-ri.com

the connection between the robot’s motions and the changes,
happening in the scene. Details on the training tasks can befound in [1]. While the robots differed in shape and size, wekept all other parameters as similar as possible, using the same
synthesized speech utterances, similar gestures, same simulated
learning rate etc.

Abstract—In this paper, we compare user behavior towards thehumanoid robot ASIMO and the dog-shaped robot AIBO in a
simple task, in which the users has to teach commands andfeedback to the robot. (Abstract)
Keywords: Human-Robot Interaction; Humanoid; User StudyI.

We have conducted experiments with 16 participants aged
from 22 to 52. Ten participants interacted with ASIMO (3males, 7 females) six with AIBO (2 males, 3 females) forroughly 45 minutes. The language used in the experiments wasJapanese. All participants were employees of the Honda
Research Institute Japan. Fig. 1 shows the experimental setting.

INTRODUCTION

Different factors influence how people interact with robots.
Studies such as [2][3] showed that the appearance of the robot
plays an important role for the behavior of users. As a part ofour work on learning commands and feedback for human-robot
interaction, we conducted a user study on how participants givecommands and feedback to the robots AIBO and ASIMO.
AIBO is a dog-shaped robot, made by Sony, which has roughly
the size of a cat or small dog. ASIMO is a 1,30m tall humanoid
robot created by Honda.
II.

III.

RESULTSIn our user study, we obtained two different kinds ofresults: We asked the participants to answer a questionnaire
about their subjective impression of the interaction and weannotated the data, which was recorded during the interaction,
to find objective similarities and differences in the participants’behavior. We used the T-Test to determine the statisticalsignificance of the observed differences.

OUTLINE OF THE STUDY

The goal of our study is to find differences and similarities
in user behavior when the participants give commands andfeedback to ASIMO or AIBO. The users interacted with either
ASIMO or AIBO and instructed the robot perform different
household tasks like bringing a coffee, switching on the light or
the TV, tidying up objects etc. and gave feedback to the robot
for correct or incorrect performance. In order to avoid timeconsuming and error-prone task execution and because of thedifferent physical capabilities of the two different robots, we
decided to use “virtual training tasks”. The tasks are shown ona screen, and the robot acts in front of the screen using gesturesand speech. On the screen, the robot’s actions are visualizedwith a hand or paw icon, so that the user can easily understandA. Questionnaire results
From the results of the questionnaire, we can see a slighttendency towards better ratings for the interaction with AIBO.
However, none of the differences is statistically significant.
B. User behavior
We analyzed different aspects of the users’ commands andfeedback that we assumed to be related to the perceived
intelligence and human-likeness of the robot. We compared thespeaking speed (in seconds per word) and the number of words
per command/feedback, as we estimated that people talk slower
TABLE I.

USERS’ RATINGS OF THE INTERACTION

Question

ASIMO

AIBO

(5: fully agree – 1: do not agree)

mean (stdev)

mean(stdev)

I enjoyed teaching the robot through thegiven task
The robot understood my feedback
The robot learned through my feedback
The robot adapted to my way of teaching
I was able to instruct the robot in anatural way
The robot took too much time to learn
The robot is intelligent
The robot behaves autonomously
The robot behaves cooperatively
Figure 1. Experimental Setting

978-1-4244-4893-7/10/$25.00 © 2010 IEEE73

3.5 (0.8)

4 (0.8)3.6 (0.9)
3.2 (1.3)
3.2 (1.1)
3.6 (1.1)

4.3 (1.1)
4.3 (0.5)
3.8 (1.3)
3.5 (1.5)

3.6 (1.4)
2.7 (1.3)
2.7 (1.4)
3.7 (0.8)

2.7 (0.9)
2.8 (1.5)
2.8 (0.9)
3.3 (0.7)

TABLE III.

and in simpler sentences, when they consider the robot lessintelligent. However, we found, that the length of commands
was almost the same for both robots. An average command for
ASIMO was 3.75 (sd=0.42) words long, while an averagecommand for AIBO was 3.72 (sd=0.71) words long. The
speaking speed was also similar for AIBO with 0.45 (sd=0.09)
seconds per word, and ASIMO with 0.42 (sd=0.07) seconds perword. This is in line with the participants’ subjective evaluationof the robots’ intelligence as shown in Table 1.

TypePersonal
Performance evaluation
Explanations

IV. DISCUSSION
While especially the way of uttering commands seems todepend rather on personal preferences of the user, than on theappearance of the robot, we found robot-dependent differencesin the feedback, given by the participants. The most obvious
one was the frequent use of touch for giving feedback to AIBO,
while touch was almost not used for ASIMO. Moreover, wefound, that users tended to give personal feedback like “Thankyou” to ASIMO, while they rather commented on theperformance when giving feedback AIBO. These findings
suggest that people actually use their experience with real dogs
as a guideline when giving feedback to AIBO.
The users’ subjective evaluation did not reveal significant
differences between ASIMO and AIBO. As both robots were
programmed to behave in the same way on the same task, we
assume, that the users’ impression of the robot’s behavior
depends more on its actual performance than on its appearance.
There are different possible explanations, why nosignificant differences were observed for giving commands.
One of them is that both robots used speech to communicate
with the user. As speech is a typical human modality ofinteracting, differences might have been stronger, if AIBO had
communicated with the user in a more dog-like non-verbal way.

COMMAND TYPES
ASIMO
75.01 (14.00)
9.86 (10.88)
10.23 (3.51)
3.40 (4.82)
6.78 (2.25)
1.81 (3.90)

AIBO
24.83 (27.41)
70.02 (28.16)
3.56 (3.90)

We found statistically significant differences (5%-level) for
the usage of personal rewards and rewards, which comment on
the robots performance. While the users usually gave feedback
like “well done (yoku dekimashita)” or “good (ii yo)” to AIBO,
they used personal rewards like “Thank you (arigatou)” for
ASIMO, especially for positive reward. While the participants
gave more explanations when talking to ASIMO, especially for
negative rewards, the difference between both robots was notstatistically significant2) Verbal commands
We analyzed, how many commands had explanations orpolite expressions and how many commands were put as aquestion. We assumed that users might be more polite, explain
more and use more questions when talking to a humanoid robot,
while they rather give plain commands to a dog-like robot. We
considered commands that contain words like “…kudasai”,“…kureru?”, “…moraeru?” etc., which are similar to theEnglish word “please” as polite commands. We also analyzed,
how many commands were given implicitly, e.g. saying “it is
too dark here” when the user wants the robot to switch the lighton, and in how many commands some expected parameters
were left out like in “put away the toy car” instead of “put thetoy car into the box”, because we assumed, that this kind ofverbal behavior might be related to the perceived intelligenceof the robot. The results can be found in Table 2.
Type
Plain commands
Polite commands
Questions in commands
Implicit commands
Parameters left out
Explanations in commands

ASIMO
52.78 (17.99)
38.39 (18.28)
11.10 (14.29)

All values in percent, values in brackets show the standard deviations

1) Multimodality
During the interaction with both robots, we did not observe
pointing gestures from any of the users. A possible explanationis that all objects were very easy to distinguish verbally, so thatpointing gestures would have been redundant. We observed
touch-based rewards for only one out of ten participants for
ASIMO but for five out of six participants, who interacted withAIBO. As touch is frequently used with real dogs, we assume
that users considered touch to be appropriate for giving
feedback to AIBO because of its dog-like appearance.

TABLE II.

REWARD TYPES

AIBO
60.83 (41.04)
26.23 (41.99)
8.34 (6.73)
4.10 (7.23)
4.13 (4.77)
0.95 (2.32)

V.
[1]

All values in percent, values in brackets show the standard deviations

The values do not add up to 100% because not all types ofcommands are mutually exclusive. While we observed quite
different utterances for different users, the differences seemed
to be rather caused by personal preferences, than by theappearance of the robots. This assumption is supported by thehigh standard deviations between users. None of the observed
differences was statistically significant.

[2]

[3]

3) Verbal positive and negative feedback
We distinguished three different types of feedback:
Personal rewards like “Thank you”, feedback which directly
comments on the performance of the robot, like “Well done.”or “That was wrong.” and explanations used as rewards like“That is not a toy car, it is a ball.” or “That is a toy car”.

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REFERENCES

A. Austermann, S. Yamada, Learning to Understand ParameterizedCommands through a Human-Robot Training Task, IEEE International
Symposium on Robot and Human Interactive Communication(ROMAN’09), 2009
Takayuki Kanda, Takahiro Miyashita, Taku Osada, Yuji Haikawa, andHiroshi Ishiguro, Analysis of Humanoid Appearances in Human–RobotInteraction, IEEE TRANSACTIONS ON ROBOTICS, VOL. 24, NO. 3,JUNE 2008
J. Goetz, S. Kiesler, and A. Powers, Matching robot appearance andbehavior to tasks to improve human-robot cooperation, IEEE Workshop
on Robot and Human Interactive Communication (ROMAN’03), 2003.