Influence of body orientation and locationof an embodied agent to a user
Satoshi V. Suzuki
National Institute of Informatics
ssv@nii.ac.jp
http://www-kasm.nii.ac.jp/∼ssv/
Miyoko Nakamura
Keio University
miyokon@sfc.keio.ne.jp

Yasunori Morishima
International Christian University
morishima@icu.ac.jp

Naotake Tsukidate
International Christian University
naotake@ta3.so-net.ne.jp

Hideaki Takeda
National Institute of Informatics
takeda@nii.ac.jp
http://www-kasm.nii.ac.jp/∼takeda/

Abstract
We attempted to suggest design of embodied
communication of an embodied agent so that auser and the agent can establish equal social relationships in this study. To design human-agent
social interaction considering the influenceof human-agent embodied communication
is important to construct human-agent equalsocial relationships. We especially focused on
body orientation of the embodied agent anddepth-dimensional virtual space partitioning
and location of the agent in near or far sideof the partition, considering gender difference
in influence of body orientation and locationin human-agent dyadic conversation.
Anexperiment (N = 48) to examine the influence of these factors to performance of work
(picture recognition task) and impression of
the agent was conducted. The result of theexperiment suggested tendency of facilitationof task performance in vis-à-vis arrangement
between the user and the agent and agent’s
presence in the near side of the partition
regardless of gender, and salient preferenceof correspondence of body orientation andlocation in female participants. This tendency
was slightly different from the influence of bodyarrangement in human dyadic conversation.
This result should be considered in designof human-agent embodied communication.

Keywords: embodied agent, embodiment,
embodied communication, social response tocommunication technologies

1

Introduction

Social actors, artifacts whose behavior induces
social response by human interactants such as
embodied agents, humanoid robots, computers,
and so on, and human interactants should bein the same standpoint to succeed communicating socially. First, there are some studies
which attempted to situate a user and an embodied agent in the same standpoint with showing empathic facial expression of the agent tothe user [10]. Some other studies revealed thatsocial actors as “teammates” can interact withpeople smoothly [15, 11], and have potential tochange attitude and behavior of interactants [5].
The social role of “teammates” enables people
to recognize that they and the social actors are in
the same standpoint. Such social actors which
act in the same way as interactants can maintain and promote good social relationship between the interactants and themselves. Therefore, designing social relationships so that people and social actors are in the same standpointis needed.
Among many social actors, we shed light onembodied agents. Softwares for speech interaction, navigation, presentations, in which embodied agents appear, has been increasing [3, 14].
However, few studies have paid attention to social influence of embodied agents’ body expression which can change user’s attitude and behavior [21, 20]. Therefore, when designing embodied agents for information navigation and learning softwares, investigating the social influenceof embodied agents via their body expression
is meaningful. We inspected social influenceof body orientation and location of embodied
agents to a user. We focused on body orientation of the agent which shows agent’s back sothat the gaze direction of the user matches the
body orientation of the agent. Similarly, we took
note to body location of the agent so that theuser can perceive that he/she shares the same
virtual space with the agent. we attempted to express that the embodied agent is user’s peer. We
conducted a psychological experiment to examine how the user pays attention to the embodied
agent whose body orientation and location corresponds with the user’s in order to determine
how the body orientation and location of theagent influences the user’s attitude and behavior. Also, the influence of agent’s body orientation and location can depend on user’s gender,
we considered gender difference in the influenceof the agent.

2

In this article, first, we review some studies
on social influence of human body orientationand location and its difference between females
and males. Second, we propose the hypothesisthat the body orientation and location of embodied agents influence user’s attitude and behavior. Third, based on this hypothesis, we describe
the psychological experiment that we conducted
to examine the influence of the body orientation and location of an embodied agent to theuser’s attitude and behavior from behavior of theagent. Next, the results of the experiment are described, and we then discuss the social influenceof the body orientation and location of the agent
and the possibility of interaction design to situate the user and the agent in the same standpoint.

2.2

Related work

In this section, we introduce some related work
regarding to social influence of human body orientation and location, and body expression of asocial actor. We mention dependence on user’s
gender difference in such social influence of asocial actor.

2.1

Influence of human body orientation

Arranging bodies of two people in the sameorientation often represents that they are in thesame standpoint. For example, in some storesof jewelry and cosmetics, customers and clerks
can match their body orientations by removing
a counter [22]. In such an environment, thecustomer can regard the clerk as more familiar
than when the customer and the clerk are faceto-face over the counter. Kendon [7] defined Fformation, that is, people’s body location andorientation so that they can converse equally, directly with identifying who are involving in theconversation. Especially, side-by-side arrangement, one of the F-formation, appears in dyadic
conversation against a wall. This evidence suggests that matching body orientation between
two people means that they are close.
We predicted that correspondence of bodyorientation between a user and an embodied
agent enables the user to share social perspectivewith the embodied agent, and induce the user tochange his/her attitude to accept the embodied
agent’s opinion.

Influence of human body location

Users can perceive distance between an embodied agent and themselves not only with rulesof perspective, but by partitioning virtual space
depth-dimensionally and where the agent appears in the partition. According to rules of perspective, users perceive distance between themselves and human figures in a display [15]. The
rules of perspective can be applied to humanagent distance. Moreover, user’s criterion ofperception of human-agent distance can change
by partitioning space and where the agent appears in the partition. Shinozawa, et al. [16]indicated that when information recommendation in a display by the embodied agent in thedisplay was more acceptable for human interactants than the recommendation in the display by
the humanoid robot out of the display. In thiscase, the human interactants should perceive thedisplay as separator of the space. The experiment indicated that if both agents appear on only
one partition, users can regard them that as having similar thoughts; if one agent appears on
one partition and the other agent appears on theother space, users can regard them that as having
different thoughts. However, the study which
discusses influence of the depth-dimensionallypartitioned virtual space to the users does notstill exist. This article suggests the following
hypothesis: if the virtual space is partitioned
depth-dimensionally, users can regard near sideof the partition as users’ and cannot regard far
side of the space as users’. Then, if the agent
appears near side of the partition, the users canregard themselves and the agent are in the same
standpoint. This study attempts to examine thishypothesis.

2.3 Influence of body expression of a social actor
In one-way visual media from a sender to a recipient, directing body orientation of charactersin the media to the recipient can induce recipient’s strong impression about the characters. In
fact, this design principle of the body orientation of the characters is applied to picture [18]and movie [1]. However, this principle refers to
influence to arousal of the recipient, not valenceof the recipient. In other words, this principle
does not explain the influence of the body orientation of the characters to the positive or negative evaluation of the characters by the recipient.
Additionally, this principle does not consider interactivity in the media.
Considering interactivity in human-agent interaction, the design of body orientation and location of embodied agent should be discussed
based on the argument in Section 2.1 and 2.2.
Some studies show evidence that body orientation correspondence between a person anda social actor induces positive impression on
him/her. Kanda, et al. [6] implemented a humanoid robot which navigates a human guest ina place unfamiliar to the guest, and suggested
that body orientation correspondence between

the guest and the robot can cause positive impression about the robot to the guest. Similar tendency of body orientation correspondence
between a human interactant and a social actor
can also occur when a social actor is an embodied agent. Miyazaki [9] conducted an psychological experiment which a participant tried
to write a story based on a picture book without text, and found that the participant tended
to write a story from first-person perspectiveof a character when the character showed its
back to the participant. Okamoto, et al. [13]implemented movie contents which embodied
agents appear with corresponding body orientation between audiences and one of the agentsso that the audiences can have empathic emotion to the agent. Although they implemented
movie contents featuring human-agent body orientation correspondence, they did not examine
whether the audiences could become empathic
with the agent in the movie contents. Suzuki and
Takeda [19] suggested that human-agent bodyorientation correspondence can induce user’s attitude change by suggestion of the embodied
agent in a psychological experiment. However,this experiment was conducted with the content
of dyadic conversation by two embodied agentsin vis-à-vis body orientation one of which always agree with participant’s suggestion and theother of which always disagree with it, and suchroles of the agents influenced the experimental
result more strongly than the body orientation of
the agent. In the experiment in this paper, only
one embodied agent appeared to exclude the influence of the agent whose body orientation did
not correspond with the user. In addition, to
exclude the influence of perceived distance between the user and the agent based on rules ofperspective, we take into account the influenceof partitioning virtual space and body locationof the agent.
Furthermore, one of the important factor inperceived psychological distance between a user
and an embodied agent is perceived immersiveness in virtual space. In most cases, the user
exists in physical space and the agent exists in
virtual space. In this environment, human-agent
interaction cannot be implemented with maintaining “direct manipulation” [17] and the lackof “direct manipulation” can cause trouble inhuman-agent interaction. Then, user’s perceived

immersiveness into the virtual space can overcome the lack of “direct manipulation” and situate a user and an embodied agent in the same
standpoint. We focused on body location of theagent in depth-dimensionally partitioned virtual
space as a visual cue to induce perceived immersiveness to the user.

2.4 Difference in influence of body arrangement between males and females
Some evidences indicate that influence of human body arrangement depends on gender. Nelson and Golant [12] pointed out the following
difference in tendency of arrangement of bodyarrangement between females and males:• Men tend to keep broader personal spacethan women. In other words, men often
try to keep longer distance to others than
women.
• In dyadic conversation, women try tokeep vis-à-vis body orientation with others, while men tend to maintain side-byside body orientation instead of vis-à-vis
body orientation.
This tendency should appear in human-agent
interaction considering the principle of media
equation [15], since the style of human-agent
interaction should be different between genders [2]. We take into account this gender difference in influence of body arrangement.

3 Psychological experiment
Based on the argument on influence of humanbody location and orientation and difference inpersonal space between males and females, we
conducted a psychological experiment to examine the difference in influence of body locationand orientation of an embodied agent between
males and females.

3.1 Purpose
This experiment aimed to inspect the gender difference in influence of body location and orientation of an embodied agent.

3.2

Method3.2.1

Participants

The participants of the experiment were fortyeight Japanese undergraduate students (25 females and 23 males; mean of age: 19.4; SD ofage 1.23). They seemed to be skilled PC user
since mean of length of history of their PC usage was 6.32 (SD: 2.90) years. The participants
were randomly assigned one of the following
experimental conditions:• FRONT–THERE condition(female: n = 5; male: n = 7)
• FRONT–HERE condition(female: n = 7; male: n = 5)
• BACK–THERE condition(female: n = 6; male: n = 6)
• BACK–HERE condition(female: n = 7; male: n = 5)
3.2.2

Experimental design

In this experiment, the following independent
variables were considered:
Body orientation of an embodied agent The
agent directed its body to the participant(FRONT), or showed its back to theparticipant (BACK).
Body location of an embodied agent The virtual space where the agent appeared
was divided in depth dimension with afence. Then, the agent appeared near side
(HERE) or far side (THERE) from the participant. The size of the agent in the display
was the same between these conditions.
Participant’s gender Taking the argument in
Section 2.4 into account, we analyzed experimental data considering difference inparticipant’s gender.
This experiment was 2 × 2 × 2 ({FRONT,BACK} × {HERE, THERE} × {female,male}) between-participant design. Body orientation and location of the agent in this experiment are shown in Fig. 1–4.

Figure 1: FRONT–THERE condition

Figure 2: FRONT–HERE condition

Figure 3: BACK–THERE condition

Figure 4: BACK–HERE condition

3.2.3 Hypotheses and predictions
Based on the argument in Section 2, we propose
the following hypotheses:• User’s task performance becomes better
when the user is female and the agent
directs its body to the user; if the user
is male, user’s task performance becomes
better when the agent directs its body corresponding with the user.
• User’s impression to the agent becomes
positive when the user is female and theagent directs its body to the user; if the user
is male, user’s impression to the agent becomes positive when the agent directs its
body corresponding with the user.
• User’s task performance becomes worseand impression to the agent becomes negative when the agent appears in far side of
the virtual space than when the agent appears in near side of the virtual space.

Then, we predicted the following in the experiment:
P1 User’s performance of a picture recognition
task becomes better when the user is female
and the agent directs its body to the user;
if the user is male, user’s performance ofa picture recognition task becomes better
when the agent directs its body corresponding with the user.
P2 User’s evaluation on attitudinal measuresabout the agent becomes better when theuser is female and the agent directs its bodyto the user; if the user is male, user’s evaluation on attitudinal measures about theagent becomes better when the agent directs its body corresponding with the user.
P3 User’s performance of a picture recognition
task becomes worse and evaluation on attitudinal measures about the agent become
worse when the agent appears beyond afence than when the agent appears in frontof the fence.

3.2.4 Procedure
Participants were told that this experiment was“evaluation of Web site navigation of zoo.”
First, a participant wrote age, gender, and history of PC use on a facesheet. Next, selfintroduction by an embodied agent started. The
agent has a role of a male zoo keeper. The
self-introduction of the agent consisted of threeparts: a job which he wanted to become when hewas child (pharmacist), a field in which he majored at university (chemistry, especially about
agrichemical), and an animal which he liked(elephant). The agent started to speak when
the participant pushed the space bar for eachpart. After the self-introduction, the agent introduced animals according to the body orientation and location explained in Section 3.2.2 foreach experimental condition. Then the participant was told that memory test for the content
which the agent introduced was prepared afterward. The introduction of animals was aboutfour different kinds of animal pairs which wasbred at the same area in Japan. It takes 10 seconds to introduce each animal pair. Size of theagent was the same for each experimental condition. Speech of the agent was represented withtext and speech balloons without acoustic media. The application for this experiment was implemented with Macromedia Flash (as a projector file, full-screen).
After the introduction of animals, the participant answered a questionnaire about attitudinalmeasures about impression of the agent. The
questionnaire consisted of twenty-eight questions with 7-point scale adopted from previous
studies [11, 8]. After answering the questionnaire, the participant was asked to answer thequestion about recognition of pictures of animals which the agent introduced with choosing 8 pictures from 32 pictures. The participant
was debriefed, thanked, and dismissed after thequestion.

4 Results
4.1 Measures
The experimental results mainly consist of twoparts: one is the results of picture recognition
task (number of correct answers and numberof incorrect answers) and the other is attitudinal measures about impression of the agent.
The questions of attitudinal measures were categorized based on previous studies [11, 8],
and eliminating some questions which decrease
Cronbach’s α the answers were averaged foreach category. Then, the value of α was relatively low in some categories.
The categories of the questions are the following:
Teamwork This category consisted of threequestions: “Did you think the agent as thepartner?”, “Did you think that you look at
the animal with the agent?”, and “Did you
think you are in the same group with theagent?” (Cronbach’s α = .71).
Friendliness This category consisted of six
questions: cheerful, likable, affectionate,kind, warm, and friendliness (α = .91).
Openness This category consisted of eightquestions: responsive, openness to influence, receptive, trust, acceptable, close inpoints aimed at, and agreeable (α = .77).
Expertise This category consisted of two questions: knowledgeable and credible (Pearson’s r = .57).
Information quality This category consistedof three questions: relevant, helpful and insightful (α = .51).

4.2 Results of a picture recognition task
Table 1 shows the number of correct answers in
the picture recognition task. For both male andfemale participants, the number in the BACK–
THERE condition was relatively lower than theother conditions. Also, while the number in
the FRONT–HERE condition was obviously
higher than the other conditions in female participants, such tendency was not observed in maleparticipants. Then, three-way ANOVA was conducted for the results and main effect of bodyorientation (F(1, 40) = 6.21, p < .05), body location (F(1, 40) = 6.97, p < .05) was significant
and tendency of significance was observed atmain effect of gender (F(1, 40) = 3.50, p < .10).
No significant interactions were observed in thisANOVA.

Table 1: Number of correct answers in a picture
recognition task (SD in parentheses)
Female

THERE

HERE

FRONT
BACK

4.00 (2.00)
3.00 (1.55)

5.14 (1.21)
4.29 (0.95)

Male

THERE

HERE

FRONT
BACK

4.00 (1.15)
2.00 (1.41)

3.60 (1.14)
4.00 (0.71)

Table 2: Number of incorrect answers in a picture recognition task (SD in parentheses)
Female

THERE

HERE

FRONT
BACK

2.20 (1.10)
2.67 (2.07)

2.29 (1.38)
3.29 (1.26)

Male

THERE

HERE

FRONT
BACK

2.43 (0.98)
4.33 (2.66)

3.00 (1.00)
2.60 (1.14)

Table 2 shows the number of incorrect answers in the picture recognition task. In thefemale participants, the number in the BACK–HERE condition was relatively higher than theother conditions; in the male participants, thenumber in the BACK–THERE condition was
relatively higher than the other conditions. In
the same way, three-way ANOVA was conducted for the results, but only tendency of significance of main effect of body orientation wasobserved (F(1, 40) = 3.39, p < .10) and no significance of other main effects and interactions
were observed.

4.3 Attitudinal measures
The results of questionnaire is shown in Table 3.
Three-way ANOVA was conducted for each categories.
In Teamwork, the value in the BACK–HERE
condition and the BACK–HERE condition werehigher than the other conditions in the female
participants, while the value in the FRONT–HERE condition and the BACK–THERE condition was relatively higher than the other conditions in the male participants. In fact, the result of three-way ANOVA showed tendency ofsignificance in main effect of body orientation(F(1, 40) = 3.03, p < .10) and significant interaction between body orientation, body locationand gender (F(1, 40) = 18.38, p < .001), andmultiple comparison for each gender showed thesignificant tendency described above. No significance of other main effects and interactions
were observed.
In Friendliness, the value in the BACK–HERE condition was saliently higher thanthe other conditions in the female participants, while the value in the BACK–HERE
and BACK–THERE condition was relatively
higher than the other conditions in the maleparticipants. The result of three-way ANOVA
showed significant main effect of body orientation (F(1, 40) = 4.25, p < .05) and tendencyof significance in interaction between body orientation, body location and gender (F(1, 40) =3.79, p < .10). No significance of other main
effects and interactions were observed.
In Openness, the value in the BACK–HERE
condition was saliently higher than the otherconditions in the female participants, whilethe value in the FRONT–HERE and BACK–
THERE condition was relatively higher thanthe other conditions in the male participants.
The result of three-way ANOVA showed significant main effect of body location (F(1, 40) =5.23, p < .05) and significant interaction between body orientation, body location and gender (F(1, 40) = 9.39, p < .01). Multiple comparison for each gender showed that the value
in BACK–HERE condition was significantly
higher than that in the other conditions for thefemale participants, and tendency of significance in the difference between the value inthe FRONT–THERE condition and that in the
BACK–THERE condition for the male participants. No significance of other main effects andinteractions were observed.
In Expertise, the value in the BACK–THERE
condition was slightly lower than the otherconditions in both female and male participants. However, the result of three-way ANOVA
showed no significance of other main effects andinteractions.
In Information quality, the value in the
BACK–HERE condition was relatively higher
than the other conditions in the female participants, while the value in the FRONT–HERE
and BACK–THERE condition was relatively

Table 3: Mean values of 7-point-scale questionnaire for attitudinal measures (SD in parentheses)
FemaleTeamwork
Friendliness
Openness
Expertise
Information quality

FRONT
BACK
FRONT
BACK
FRONT
BACK
FRONT
BACK
FRONT
BACK

Male
Teamwork
Friendliness
Openness
Expertise
Information quality

FRONT
BACK
FRONT
BACK
FRONT
BACK
FRONT
BACK
FRONT
BACK

higher than the other conditions in the maleparticipants. However, the result of three-way
ANOVA showed only tendency of significancein interaction between body orientation, body
location and gender (F(1, 40) = 3.65, p < .10)
and no significance of other main effects andinteractions were observed. Multiple comparison showed that the value in the BACK–HERE
condition was significantly higher than the otherconditions for the female participants, but nosignificant difference was observed for the maleparticipants.

5 Discussion
5.1 Influence of body orientation of anembodied agent
The experimental results shown in Section 4.2
suggested that body orientation of an embodied agent can influence user’s task performanceand impression of the agent. When the agent
directs its body to the female user the information offered by the agent can impress the user.
This results partially support the prediction P1.
Besides the influence of body orientation ar-

THERE

HERE

3.33 (0.78)
2.67 (1.53)
3.97 (1.36)
3.24 (1.26)
4.90 (1.07)
4.67 (1.45)
4.80 (1.04)
4.33 (1.13)
3.87 (0.87)
3.83 (0.98)

2.19 (0.98)
4.48 (0.96)
3.45 (0.54)
4.82 (0.99)
5.14 (0.69)
6.29 (0.59)
4.93 (1.24)
5.07 (1.34)
3.95 (0.95)
4.80 (0.79)

THERE

HERE

2.38 (0.91)
3.28 (1.10)
2.76 (1.46)
3.88 (1.26)
4.38 (1.10)
5.47 (1.29)
4.57 (1.13)
4.25 (1.44)
3.67 (1.07)
4.11 (0.75)

3.60 (0.86)
2.40 (0.55)
3.14 (1.04)
3.80 (1.89)
5.83 (0.83)
4.67 (0.78)
4.70 (0.67)
4.50 (1.58)
4.27 (0.43)
3.60 (1.09)

rangement for female described in Section 2.4,
this phenomenon can be explained from two approaches. One is vis-à-vis arrangement in Fformation [7]. In human-agent interaction between physical space and virtual space, vis-àvis arrangement can be more appropriate thanother arrangement of body orientation. However, we cannot conclude vis-à-vis arrangement
is appropriate in human-agent interaction sincedifferent tendency in influence of agent’s bodyorientation was observed in attitudinal measureof agent’s impression. The other is social facilitation [23], that is, people tend to show high task
performance when others see their task performance. According to the media equation [15],gaze of the agent instead of the human gaze cancause social facilitation in user’s performance.
However, it is known that the human gaze prevents people from better performance when they
try the task at which they are poor [23]. Then,
another analysis of difference in default task performance for each user should be examined.
Besides, the body orientation of the agent
can influence not only the task performance but
user’s attitude toward the agent. According to
the results described in Section 4.3, the val-ues in indices except Expertise in the BACK–HERE condition for the female participants was
saliently higher. However, this tendency contradicts the prediction P2 since the female participant positively evaluated the agent’s impression when agent’s body orientation was corresponded with her. Although the experiment byKanda, et al. [6] suggested that body orientation correspondence between a human interactant and a humanoid robot positively influences
to his/her impression to the robot, they did not
try to examine gender difference in this influence and the experimental environment in thisstudy differs from that in their study. One ofthe possible explanation of the results is that perceived distance between the participant and theagent was different between the FRONT condition and the BACK condition besides the influence of body location. In this experimental
environment, it depended on participant’s perception that he/she located his/her body in thevirtual space where the agent existed. Then,
when the agent corresponded its body orientation to the participant, he/she might perceive thedistance between him/her and the agent shorter
than they are in vis-à-vis arrangement. This hypothesis should be examined in the future work.

5.2 Influence of body location of an embodied agent
The influence of body location was observedin the number of collect answer in Section 4.2
and the value of Openness in Section 4.3. In
these measures, the value became lower when
the agent appeared at far side of the virtual spacethan when the agent appeared at near side of thevirtual space. This fact partially supports theprediction P3. It is possible that the fence inthe virtual space was recognized as a separator
in depth dimension of the virtual space by theparticipant, and he/she perceive a long psychological distance to the agent when the agent appeared at the far side of the virtual space. However, we cannot tell whether the participant recognized the function of the fence as the separator of the virtual space when the agent appearedat the near side of the space. In addition, while
we used a laptop PC to display the agent, perceived distance between the user and the agent
can depend on size and shape of display devices,such as an immersive display like CAVE [4],mobile devices like a PDA, a cellular phone, andso on. These issues should be addressed in future work.

6

Conclusion

In this study, we discussed gender difference ininfluence of body orientation and location of theembodied agent to users with conducting psychological experiment. In this experiment, weobserved promotion of task performance whena participant and an embodied agent were in
vis-à-vis arrangement and the agent appearedin near side of virtual space, and preference ofcorrespondence of body orientation and location in female participants. To design embodied
agents for information navigation and learning
softwares considering this study should be important, with continuing the fundamental studyof human-agent embodied communication.

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