International Journal of Informatics Society, VOL.6, NO.2 (2014) 39-47

39

User’s Communication Behavior in a Pseudo Same-room Videoconferencing System
BHS
Tomoo Inoue*, Mamoun Nawahdah**, and Yasuhito Noguchi****Faculty of Library, Information and Media Science, University of Tsukuba, Tsukuba, Japan**
Faculty of Engineering and Technology, Birzeit University, Birzeit, Palestine***
Graduate School of Library, Information and Media Studies, University of Tsukuba, Tsukuba, Japan*inoue@slis.tsukuba.ac.jp, **mnawahdah@birzeit.edu, ***noguchi@slis.tsukuba.ac.jp
Abstract - This paper presents user's communication
behavior in a pseudo same-room videoconferencing named“Being Here System,” in comparison with a conventional
videoconferencing. The system extracts the remote person's
figure and superimposes it on the local site's front view in alarge display in real-time. This method makes the local
person feel as if the remote person was before him/her in
his/her spatial environment. To investigate the influence ofthe system on user’s communication, the recorded video ofthe system evaluation experiment was analyzed. Thisrevealed that the system significantly affected user's
communication behavior such as turn taking, speech overlap,
and gaze directions 1.

Keywords: Videoconferencing, presence, video overlay,
telecommunication, Kinect application

1

INTRODUCTION

Communication can be carried out in face-to-face (F2F) or
through media. In F2F communication, the exchange of
information, thoughts, and feelings is made when theparticipants exist in the same physical space at the sametime. In this communication, nonverbal cues (e.g., eyecontact, facial expression, body movement, interpersonal
distance, etc.) may influence the way the message isinterpreted by the receiver. In contrast, although mediatedcommunication including videoconferencing provides
people with many advantages given the increased
globalization and the need for rapid knowledge transfer
across borders and time zones, the absence of nonverbal
cues may make communication difficult. Hence
communication process is affected in mediatedcommunication. A person may feel less presence of remoteparticipants in mediated settings, and he/she may fail tointerpret other people's behavior correctly and/or accurately.
Therefore, one of the design goals of a videoconferencing
system is to create a medium setup that is as close as
possible to F2F.
Many studies have suggested that generating a life-sizedview is likely to enhance the user's sense of presence [8, 12,
13, 24, 11, 16]. Here “presence” or “sense of presence”
refers to the user's feeling of connection to the remoteperson with whom they are interacting [18]. The life-sized

1 This research was partially supported by the JSPS Grant-in Aid

for Scientific Research 26330218.

Figure 1: A user talks to a remote user through BHS.
view makes it easy to read the other person's behavior that isessential for smooth communication.
Large displays can be used to achieve a life-sized view.
However, this means that a considerable region of the local
person's front view is replaced by the remote site's
background, which makes no integration or continuity in thelocal person's front view. This may decrease the user’s senseof co-presence. Meanwhile, the remote site's background insome environments might be 'cluttered' with static or
movable objects. This may either be a distraction or be moreengaging, giving a greater sense of the other person'senvironment [5].
“Being Here System (BHS)” is a system to achieve
pseudo same-room videoconferencing system using a large
display [23]. The system provides the communication
environment where the remote user's life-sized figure isvisually situated in the local site (Fig. 1) and vice versa. The
display shows the local site's front view, which would
otherwise have been obstructed by the display, as a
background. In this way, the user feels as if the remote user
is present before him/her in the same room. In other words,
the user feels co-presence of the other remote user. BHS was
initially evaluated by a questionnaire filled by users after
performing a videoconferencing experiment. The
questionnaire results revealed that BHS achieved higher
sense of co-presence of remote users than the conventional
videoconferencing system.
In this paper, we further investigated the user's behaviors
when communicating using BHS. The motivated question iswhether
BHS
affects
verbaland/ornonverbal
communication
structure.
The
consideredverbalcommunication parameters in this study are turn taking,speech time, and speech overlap. Regarding nonverbal

ISSN1883-4566 © 2014 - Informatics Society and the authors. All rights reserved.

40

T. Inoue et al. / User’s Communication Behavior in a Pseudo Same-room Videoconferencing System BHS

parameters,gaze
directionisconsidered.
The
communication behavior analysis revealed that BHS hassignificantly affected users’ conversational behaviors.

2
2.1

RELATED WORKSMedia Space Systems

There have been various studies done on remotecommunication and media spaces, and a host of systems
have been developed over time. Many of these studies havebeen devoted to proposing and/or implementing methods
aimed at enhancing the sense of presence invideoconferencing.
One early system called “Hydra” sought to enhance thesense of presence by supporting directional gaze cues andselective listening in 4-way videoconferencing [27]. A
multi-party videoconferencing system called “MAJIC” wasconstructed by Okada et al. to support eye contact [24]. In
this system, life-sized video images of participants were
projected onto a large curved transparent display. Anotherline of research focused on the seating arrangement invideo-mediated meetings, in order to enhance the sense ofpresence [12]. The system was designed for multiple
participants so that the video image of any remoteparticipant be always placed where a viewer need to makeno effort to see it. A different approach to enhance the senseof presence was introduced by Morikawa et al. [20]. In thisstudy, a system called “HyperMirror” was constructed, inwhich all participants were meant to feel as if they weresharing the same virtual space. To provide a greater sense ofpresence than had been achieved with conventional desktop
videoconferencing, Gibbs et al. created the “TELEPORT”
system [8], which was based on special rooms, called
display rooms, in which one wall was a “view port” into avirtual extension. A side-by-side media space concept was
proposed to enhance the presence feelings, which was
suggested to be more appropriate for side-by-side styleinteractions such as collaborative writing and training [28].
Other effective attempts to enhance the presence feelings
involved movable displays [22] and movable cameras [21].
It is natural to devote more attention to people present
before one, since the felt presence of remote people isconsiderably weaker [32]. To overcome this inclination,
robotic means have been employed to convey the sense ofpresence in videoconferencing, enhancing the remotepeople's felt presence. In this regard, a study by Sakamoto etal. investigated the effect of using a humanoid robot system
as a telecommunication medium [26]. Another study, byYankelovich et al., introduced a system called “Porta-Person”
to enhance the sense of social presence for remote-meeting
participants [32]. This goal was achieved by providing ahigh-fidelity audio connection and a remotely controlled
telepresence display with video or animation. In the samemanner, Venolia et al. developed a telepresence device,called “Embodied Social Proxy (ESP)”, which represented aremote coworker at roughly human-scale [29]. In thissystem, they found that the physical presence of the ESP
was a powerful reminder of the presence of the remoteworker in the meetings.

The studies and implemented systems above focused
primarily on creating a high-presence media space. Our
study, in turn, makes its own contribution to this field. To
mimic real situations, the remote person's figure should bepresented locally, without his/her remote background.
Typically, this can be achieved by using mixed-reality (MR)technology and special head-mounted display (HMD)
equipment [11, 4, 15]. Using HMD for some people might
be encumbering and uncomfortable. This setup is likely todecrease the sense of presence. In contrast, our proposedsystem can be easily implemented in both sites, allowing
both participants to experience the same effects.

2.2

Commercial Videoconferencing

In commercial videoconferencing business firms, manysolutions have been introduced under the name
“Telepresence” technology for high presence feelings.
Telepresence is defined as an illusion that a mediatedexperience is not mediated [18]. In videoconferencing
experience, telepresence gives you the feeling as if theremote participants are in the same room with you. To create
the same-room illusion, some commercial telepresence
solutions use a combination of technology elements, such asutilizing large displays for life-sized dimensions and hidden
high-definition cameras strategically placed to create theappearance of a direct eye contact, and environmental
design, such as consistent furniture arrangements acrosslocations. The life-sized dimensions allow participants tosee facial expressions, make eye contact, and read bodylanguage. Such solutions are: Cisco TelePresence TX9000
Series 1 , Polycom® RealPresence™ Immersive 2 ,TANDBERG3, PeopleLink TelePresence4 , etc.
In one hand these solutions simulate high presence
meeting environments as if the other people were sitting
across the table in the same room. But on the other handthese solutions are very expensive, require large-spaces, andhave to be installed in a fixed environment with pre-installed
matching furniture in both sides to achieve maximum
telepresence feelings. In contrast, BHS can be implemented
using an affordable equipments and can be installed easily
almost anywhere.

2.3 Verbal and Nonverbal Communication
Analysis
It's well known that in F2F communication, people
switch speaking and listening by using a complicatedmechanism of verbal and nonverbal cues [2]. A major
nonverbal cue in speaking involves the use of eye contact[1]. In F2F communications, failure to maintain eye contact
is commonly considered to be a sign of deception, and leads
to feelings of mistrust [2]. Vertegaal et al. concluded thatgaze is an excellent predictor of conversational attention in
multiparty conversations [30]. A study by Karmer et al.
1

http://www.cisco.com/en/US/products/ps12453/
http://www.polycom.com/products/telepresence/_video/3
http://www.tandberg.com/
4
http://www.peoplelink.in/telepresence.html
2International Journal of Informatics Society, VOL.6, NO.2 (2014) 39-47

41

Figure 3: The 30 inch portrait display setup.

Figure 2: The process diagram of BHS.
proposed a method of measuring people's sense of presencein videoconferencing system based on linguistic features of
their dialogues [17]. This study shows that 30% of thevariance in self-reported presence can be accounted for by asmall number of task-independent linguistic features.
The seating arrangements on group video communication
affect participant's behaviors as well. A study by Inoue et al.
presented a videoconferencing system “HERMES” that
integrates F2F and video-mediated meetings [12]. In This
study they observed that participants tended to pay muchattention to the monitor when using lined-up seating
arrangement. This problematic behavior solved by the
combination of round seat arrangement and multiple
monitors. Another study by Yamashita et al. revealed thatseating arrangements affect speaker switches without verbal
indication of the next speaker [31]. This study found that insome seating arrangement, the participants shared a higher
sense of unity and reached a slightly better group solution.
Our study as well examined the proposed high-presence
videoconferencing system for any verbal and/or nonverbal
effects on communication comparing with a conventional
videoconferencing system.

3

BEING HERE SYSTEM

A videoconferencing system “Being Here System (BHS)”
was constructed to achieve pseudo same-room environment
to the users. The two sites, 'Site A' and 'Site B', wereconnected over a local network to permit the exchange oflive video. Each site was equipped with a display installed
upright 70 cm above the floor, a USB camera, a Kinect™
RGB-D camera, a computer connected to the network, a
speaker and a microphone, and a chair. The user was seated
at 1.2 m distant from the display since this was considered
to be appropriate distance for F2F meetings [10].
The process diagram of BHS is shown in Fig 2. We used
the USB camera to capture the local site's front view, that is,
the region concealed behind the display. The USB camera
was placed behind the display in the center, and the camera's
angle and zoom were calibrated so that the region behind thedisplay was exclusively captured. This captured image (640by 480 pixels) was used as a background for the display.
To capture the site view and extract the user's figure fromit at run-time, the Kinect was used, which was placed
centrally over the display and focused on the person's face.
OpenNI API was used to analyze the Kinect image depth
data by identifying the user in the scene and replacing thebackground with a transparent color. The resulted image
was transmitted to the other site at 15 frames per second.
The final step in the process was to superimpose thereceived remote user figure onto the local front view. This
was accomplished by merging the extracted user's figure andthe background. Finally, the processed video was presented
on the large display.
With this simple system architecture, the system is
supposed to be expanded to the multi-point conferencing
easily. This is a noteworthy feature that other existing
systems have not achieved because of their limited spatialalignment and/or expensive customized devices.

4

SYSTEM EVALUATION

An experiment was conducted to evaluate BHS. The main
objective of this experiment was to study the influence of
BHS on user's communication behavior in comparison withconventional videoconferencing. Two remote sites, Site A
and B, were constructed. In Site A, a large flat-panel display(46 inches) was used (Fig. 1), while in Site B, a 30-inch
display was used. The 30-inch display was fixed in a vertical
portrait position, presenting a life-sized image of an adult's
upper body (Fig. 3). We used the portrait mode to study theeffects of different background sizes.

4.1 Conditions
Two videoconferencing modes, “Conventional mode”
where the remote site view was displayed in the local site's
display and “Superimpose mode” where the remote person's
figure was extracted and superimposed on the local site's
front view, were established.
In the experiment, we considered the following
videoconferencing conditions:•Large Superimpose (LS): superimpose mode via large
display.
• Portrait Superimpose (PS): superimpose mode via
portrait display.

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T. Inoue et al. / User’s Communication Behavior in a Pseudo Same-room Videoconferencing System BHS

4.4

Figure 4: The participants' average sense of presence
results (Note: Q2' result is the positive form of theoriginal Q2).
•Large Conventional (LC): conventional mode via large
display.
• Portrait Conventional (PC): conventional mode via
portrait display.

4.2 Participants
Nine pairs, 7 females and 11 males whose ages ranged
from 23 to 36 years old and who were familiar with eachother, took part in the experiment. Among them, 17participants had experience using videoconferencing
systems. Most used the videoconferencing principally to talkto remote family members and/or remote close friends.

4.3 Procedure
One of the pair used the system at Site A, while the otherused Site B. Before performing the videoconferencing tasks,
the participants were asked to complete a basic demographic
survey. After this, the experimenter introduced the system tothe participants. The experiment began with afamiliarization session. Each participant performed four
videoconferencing sessions to test the conditions. In eachsession, participants were instructed to talk about a selected
general topic for approximately 10 minutes. After that they
were asked to complete the questionnaire about the system.
The four general topics were:Study life in X city: discuss with the other person thepros and cons of studying in X city; how long you havebeen in X city; why you choose X university, compare X
city with other cities you have been in, etc.
Buying a new laptop: discuss the laptop's specifications;the suggested shops; prices; usage; etc.
Planning a trip: for the coming summer vacation, discuss
the trip's options; where to go; locally or abroad; cost;
weather; attraction; etc.
Plans after graduation: discuss with the other person
your plans after graduation, the possibility of pursuing ahigher degree; work options, etc.
The conditions orders were randomized to ensure that theorder of the tested conditions would not affect the result.

Questionnaire

In the questionnaire, we asked participants to evaluateeach of the statements according to the feeling theyexperienced during the videoconferencing session. To
investigate the participants' sense of co-presence in eachcondition, the following statements were used [10]:•Q1: “I felt as if the other person existed in the sameroom.”•Q2: “I didn't feel as if I were talking with the otherperson in the same room.”•Q3: “I felt as if I were facing the other person in thesame room.”
The perceptual distance between the participants is an
aspect of the sense of co-presence. To evaluate this, thefollowing statements were used:•Q4: “I felt that the distance between me and the otherperson was comfortable for chatting.”•Q5: “I felt that the distance between me and the otherperson was around:__________ ”
All of these statements, except Q5, were rated on a 9point Likert scale, where 1 = strongly disagree, 3 = disagree,
5 = neutral, 7 = agree, and 9 = strongly agree.

4.5

Videotaping

Two cameras were used to record the experimentsessions at HD 720 resolution (1280 by 720 pixels). The
first camera was placed over the display facing theparticipant in order to capture his/her facial expressions,
gestures, and postures. The second camera was installed
upright 1 m above the floor beside participant in order tocapture him/her from the side and the display content.

5
5.1

RESULTS
Questionnaire

Figure 4 shows the average results of the participants'
sense
of
the
other
person's
presence
while
videoconferencing, under the four conditions. A comparison
was done using two-factor ANOVA test. The first factor isthe videoconferencing mode (i.e. Conventional andSuperimpose). The second factor is the used display (i.e.
Large and Portrait). We found main effect ofvideoconferencing mode over the participants' sense of otherperson's presence as if in the same room (Q1: F(1,68) =55.26, p<0.01, Q2': F(1,68) = 14.08, p<0.05, Q3: F(1,68) =31.71, p<0.01). This indicates that the superimposed
videoconferencing mode enhanced the presence feelings
more than the conventional videoconferencing mode. On theother hand, the results shows no main effect of the useddisplay (Q1: F(1,68) = 0.31, Q2': F(1,68) = 0.0, Q3: F(1,68)= 0.06). The result also shows that there is no interaction
between the used mode and display (Q1: F(1,68) = 2.31,
Q2': F(1,68) = 2.73, Q3: F(1,68) = 1.34).
Moreover, we found main effect of videoconferencing
mode over the feeling of comfortable distance between theuser and the other person (Q4: F(1,68) = 7.14, p<0.01),
while no main effect of the used display (Q4: F(1,68) =International Journal of Informatics Society, VOL.6, NO.2 (2014) 39-47

Figure 5: Screenshot of one of the ELAN's annotatedvideo.
0.89). The result also shows there is no interaction between
the used mode and display (Q4: F(1,68) = 0.62). This
indicates that the superimposed videoconferencing modeenhanced the feeling of comfortable distance between theuser and the other person. In addition, participants who used
the superimpose videoconferencing mode were able toestimate the distance more accurately. The average
estimated distances were as follows:• LS: 1.3 m (s.d. = 0.6).
• PS: 1.3 m (s.d. = 0.6).
• LC: 2.2 m (s.d. = 1.2).
• PC: 1.8 m (s.d. = 1.0).
(The actual distance between the participant and thedisplay was 1.2 m).

43

Figure 6: The participants' average number of turn taking
per minute.

Figure 7: The participants' average speech rate.

5.2

Communication Behavior

Communication behavior was analyzed quantitatively
using the recorded video. ELAN1 was used to annotate thevideo. A total of 36 recorded videos from 9 pairs by 4
conditions were annotated for user's communication
behaviors such as speech and gaze. The middle 2 minutes ofeach session was analyzed, which resulted in a total of 72
minutes data. Figure 5 shows a screenshot of one of the
ELAN's annotated video.
The following aspects were used for the analysis:• Speech: happens when a person speaks for at least
1.5 seconds [14].
• Turn taking: is defined as the manner in which
orderly conversation normally takes place. The
principles of turn-taking were first described bysociologists Sacks et al. in [25]. In this study, we
adopted the same turn definition with [27] as the
person's number of continuous segment of speech
between silent intervals for at least 1.5 seconds.
• Overlap: is a simultaneous speech by two persons.
This might happen when taking turns or when
responding to other person's speech while talking.
• Gaze: happens during a conversation when a person
look at the other [1].

• Gaze aversion: this term is defined for the analysis in
this paper. It happens when a person averts his/hergaze from the other.

5.3

SpeechFigure 6 shows the average results of the participants'
number of turn taking per minute under the four
videoconferencing conditions. A comparison among theconditions was done using one-way repeated-measures
ANOVA test. We found significant difference in the numberof turn taking (F(3,51) = 6.49, p<0.05). From Tukey’s HSD
post-hoc test, the superimpose conditions were significantly
different from the conventional conditions.
Figure 7 shows the average results of participants'
percentage of individual speech. We found no significant
difference between the conditions (F(3,51) = 0.48).
Figure 8 shows the average results of the participants'
percentage of speech overlap. We found significant
difference in the percentage of speech overlap (F(3,51) =11.69, p<0.01). The superimpose conditions weresignificantly different from the conventional conditions.

5.4

Gaze

Figure 9 shows the average results of the participants'
number of gaze aversion per minute. We found a significant
1

http://tla.mpi.nl/tools/tla-tools/elan/

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T. Inoue et al. / User’s Communication Behavior in a Pseudo Same-room Videoconferencing System BHS

questionnaire results between the large conventional
condition and the portrait conventional condition could be
explained by this, although the differences are notstatistically significant.

6.2

Figure 8: The participants' average percentage of speech
overlap.

Figure 9: The participants' average number of gazeaversion per minute.
difference in the number of gaze aversion (F(3,51) = 4.83,
p<0.05). The superimpose conditions were significantly
different from the conventional conditions.

6

DISCUSSION

6.1

Display Size

We expected that the results could be different dependingon the display sizes because of the different backgroundsizes. One participant mentioned that the portrait display's
frame concealed a relatively large area of the front viewcompared with the large display, which may be related tothe study by Bi et al. on the effects of bezels of large tiled
display that the bezels affected tunnel steering [3].
The results were, however, very similar between different
display sizes. More regions are concealed in the large
display conditions. It is expected that the superimpose modecan compensate this by displaying the front view as a
background of the display. Actually the large superimpose
condition and the portrait superimpose condition obtained
the similar results. This indicates that the display size has no
major effect as long as the displayed background is
integrated with the actual front view.
In the conventional modes, the large display shows remotesite more, which might decrease the sense of co-presencecompared to the portrait display. This was not observed in
the communication behaviors. The small differences ofCommunication Behavior

In this paper it was shown that the superimpose modesignificantly affected participants' verbal and nonverbal
communication behaviors. The superimpose conditions
increased the number of turns by around 130% more thanthe conventional conditions (Fig. 6). The participants'
average percentage of speech wasn't affected by the tested
conditions (Fig. 7). This result is consistent with a related
research by Sellen, which compared face-to-face and videomediated conversations to find no difference in speech rate[27]. Each participant spoke 48% of the session time on
average in our experiment. We found that the percentage ofspeech overlap in the superimpose conditions were twice
more than the conventional conditions (Fig. 8). Because
Cohen’s study [7] and Sellen’s study [27] found that face-toface imposes more simultaneous speech compared withvideo conditions, this can be one of the evidences that our
proposed superimpose mode could be closer to the F2F thanthe conventional mode.
Gaze is an important aspect of nonverbal communication[6, 9, 27]. We investigated the gaze directions and counted
the number of gaze aversion in this study. The result showsthat the participants tended to avert their gazes more when
they used the superimposed conditions compared with theconventional conditions (Fig. 9). In F2F conversations,people use more gaze when they are further apart [1]. Thismeans that the participants who used the superimposed
conditions might feel closer to the other person.

6.3

Multipoint BHS

BHS was a point-to-point conferencing system. However,the system was supposed to be expanded to the multi-point
conferencing easily considering its simple architecture, as
noted in Section 3. Figure 10 shows a schematic diagram ofthe multi-point BHS which does not need a network, thoughobviously the system can be expanded to multi-point using a
multicast network.
To examine its feasibility, the actual multipoint BHS was
implemented (Fig. 11). It can be observed that themultipoint BHS provides higher sense of co-presence thanthe conventional multipoint videoconferencing (Fig. 12),even from the figures.

7

CONCLUSIONIn BHS, the pseudo same-room effect is achieved bysuperimposing the remote person's figure, which is extracted
from the remote site view using the Kinect RGB-D camera,
with the local front view on a large display. BHS effectively
reduced the psychological distance between the remoteparticipants.
In this study, we investigated user’s verbal and nonverbal
communication behaviors while using BHS, in comparison
with a conventional videoconferencing. The analysis of theInternational Journal of Informatics Society, VOL.6, NO.2 (2014) 39-47

Figure 10: Design of Multipoint BHS.

Figure 11: Multipoint BHS.

Figure 12: Conventional multipoint videoconferencing.
recorded video revealed that using BHS significantly
affected user's communication behavior. This result suggeststhat considering the local site front view as a background is
one practical way to create the same-room illusion, whichfacilitates communication.

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(Received December 18, 2013)
Tomoo Inoue is Professor of theFaculty of Library, Informationand Media Science of Universityof Tsukuba. His research interests
include HCI, CSCW, andTechnology-enhanced learning.
He received his Ph.D. in
Engineering from Keio University
in 1998. He is a recipient of awards including Best
Paper Award, Activity Contribution Award and SIG
Research Award from Information Processing
Society of Japan (IPSJ). He has served a number ofacademic committees, currently including IEICE SIG
Human Communication Science, IEICE SIG
Multimedia on Cooking and Eating Activities, VRSJSIG Cyberspace, IPSJ SIG Digital Contents
Creation, IPSJ SIG Groupware and Network
Services, APSCE CUMTEL SIG, and IEEE TC
CSCWD.
Mamoun Nawahdah was born inPalestine in 1976. He received theB.Eng. degree in Computer
System Engineering from the PPU,
Palestine in 1997, the M.S. degreein Scientific Computing from theBirzeit University, Palestine in2005, and the Ph.D. degree inInformation Science from the University of Tsukuba,
Japan in 2013. In 2006, he joined the Faculty ofEngineering and Technology, Birzeit University, as a
Lecturer, and in 2013 became an Assistant Professor.
His current research interests include pair
programming, human computer interaction (HCI),
Mixed Reality, and remote communication.

International Journal of Informatics Society, VOL.6, NO.2 (2014) 39-47

Yasuhito Noguchi received his
M.S. degree from the Graduate
School of Library, Informationand Media Studies at University ofTsukuba, Japan in 2008. He iscurrently working toward Ph.D.
degree in the Graduate School of
Library, Information and Media
Studies at University of Tsukuba. His researchinterests include groupware.

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