Abstract
In recent years, opportunities for communication between humanoid robots and people are increasing. In addition, opportunities to communicate with robots autonomously operating without being manipulated by people are increasing. An important aspect of smooth communication between humanoid robots and people is personal space. In other words, it is necessary for the robot to communicate at a distance in consideration of a person’s personal space. Therefore, in this research, we focus on presence or absence of operator of the humanoid robot and investigate the influence of personal space toward the robot. Also we investigate how the person’s communication skill and sensory evaluation toward the robot affect personal space. As a result of the experiment, there is no significant difference in presence or absence of the operator in the personal space toward the robot. In addition, regardless of presence or absence of the operator, it is shown that the person who feels discomfort to the robot have a larger personal space. From these results, it becomes clear that there is a high possibility that the sensory evaluation of each individual toward the robot has a greater influence on personal space than the presence or absence of the operator.
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1 Introduction
In recent years, as robots are used more and more in various situations around us, people interact with humanoid robots on a more frequent basis, and the number of autonomously functioning robots not controlled by humans is increasing as well. Along with this popularization, researchers have investigated the effects of humanoid robots’ autonomy on people’s feelings toward robots. Kanda et al. reported that some participants behaved similarly when communicating with autonomously functioning robots to how they would with another person [1]. Additionally, it has also been reported that robots are recognized as having the same social standing as people when there is an operator alongside the robot [2].
In face-to-face communication, one key element for establishing smooth communication is personal space. Personal space is defined as the spatial area surrounding an individual’s body, and it is the boundary at which that individual does not wish other people to approach any further. Shibuya’s research shows that personal space between those familiar with each other is smaller than that between strangers, and it is also smaller among those of the same gender versus those of the opposite gender [3]. It is also said that people carry out smooth communication by subconsciously changing their personal space. From this point of view, it is clear that robots must communicate with humans from a distance that takes into account humans’ personal space. However, the influence of humanoid robots’ autonomy on humans’ personal space when with robots has not been investigated.
This research therefore focuses on the presence or absence of a human operator for the humanoid robot in terms of autonomy and investigates the influences on human’s personal space toward the robot. Moreover, we also investigate the relationship between personal space and people’s communication skills/sensory evaluation toward the robot.
2 Related Research and Research Objective
2.1 Related Research About Personal Space
Many researches have been conducted on personal space among humans, and such researches are still conducted today. There are many definitions for personal space, but in general, personal space refers to the spatial area surrounding an individual’s body [3]. People communicate comfortably by subconsciously changing their personal space. In addition, Hall classifies personal space into four zones based on how people change their personal space depending on their relationship with their companion: intimate space, personal space, social space, and public space [4]. Also, according to Shibuya’s research, introverts have smaller personal space than extroverts [3]. Moreover, personal space changes with the gender of one’s companion, with personal space between those of the same gender smaller than those of the opposite gender.
The main methods of measuring personal space include the stop-distance method, the unobtrusive observation method, the seat selection method, the felt board method, and the paper and pencil method. In the stop-distance method, a person approaches the participant who stops the approaching person when he/she feels uncomfortable or does not wish to be approached any further, and the space between the participant and the approaching person at this point is measured as personal space. This method is regarded as the most reliable way of measuring personal space [5].
While research has been conducted on personal space between people, researches on personal space between people and robots have also been conducted. Related researches show that people’s personal space with robots is an elliptical shape with the further end in the front, the same shape it is among two people [6], and it is shown to be smaller than it is among two people [7].
A person’s sense of “self” includes his or her body, but it also extends to things he or she refers to with “my” or “mine” (clothes, family, house, etc.) [8]. Similarly, Ariga demonstrates that an individual’s personal space extends to the space surrounding his or her possessions (“things”) [9]. This observation suggests that the gender and characteristics of a robot operator may impact a person’s personal space with a robot.
2.2 Related Research About Robot Autonomy
Researchers have also investigated the influence that robots’ autonomy has on people’s feelings toward robots. Fujita suggests that autonomously functioning robots may be thought of as intermediate entities between machines and humans [10]. Kanda et al. report that some participants behaved similarly when communicating with autonomously functioning humanoid robots to how they would with another person [1]. It has also been reported that robots are regarded as being similar social entities as people by virtue of having operators [2].
2.3 Research Objective
This research focused on the presence or absence of an operator of the robot, with regard to autonomy, and used the stop-distance method to evaluate the influences that the presence of humanoid robot’s operator has on personal space. In addition, personal space may also change with people’s communication skill and sensory evaluation of the robot. For this reason, we also evaluate the relationship these factors have with personal space.
3 Verification Experiment
3.1 Experiment Objective
In this experiment, we aimed to reveal what influences the presence of humanoid robot’s operator has on personal space through quantitative and qualitative evaluations, conducting sensory evaluation experiments with the participants.
3.2 Experimental Method
In this experiment, we measure personal space using the stop-distance method by having the robot approach the participant. More specifically, the participant is made to stop the approaching robot when they feel they do not want it to approach any further, and the distance between the participant and the robot at this point is measured as personal space distance. In this experiment, personal space is regarded as the horizontal distance between the participant’s head and the tip of the robot’s feet. The distance between the participant and the robot is set to 350 cm at the start of the experiment. Meccanoid G15KS constructed by the company Spin Master is used as the robot. Figure 1 shows the appearance and details of the robot used in the experiment. Meccanoid G15KS can be operated remotely using an application to control actions such as moving forward and stopping.
Appearance and specification of robot used in experiment.
Personal space is measured in three conditions: when the robot is not controlled by an operator and moved automatically (the no operator condition), when the robot is operated by a male (the male operator condition), and when the robot is operated by a female (the female operator condition). We enlist the cooperation of one male student and one female student from the Doshisha University Applied Media Information Laboratory to serve as the robot operators.
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No Operator Condition
The Wizard of Oz method is used when instructing the participant [11]. In this experiment, the participant is told that the robot is capable of voice recognition and will be moving when told “start” and will come to a stop when told “stop.” In actuality, an operator stands by in a location unseen by the participant and will start and stop the robot in sync with the participant’s voice commands. Figure 2 shows the experimental setup and scene of the no operator condition.
Experimental setup and experimental scene (no operator condition).
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Male/Female Operator Condition
The participant is instructed that the operator will maneuver the robot according to the participant’s voice commands; when the participant say “start,” the operator will move the robot forward, and when the participant say “stop,” the operator will stop the robot. In this condition, there is an operator actually controlling the robot. Because a difference in clothing between the male and female operators may impact the experimental results, both the male and female operators are made to wear a white lab coat. Figure 3 shows the experimental setup and scene of the male operator and female operator conditions.
Experimental setup and experimental scene (male operator condition and female operator condition).
3.3 Questionnaires
In this experiment, participants answer a pre-experiment questionnaire, a post-measurement questionnaire, and a post-experiment questionnaire.
In the pre-experiment questionnaire, participants answer whether they are familiar with the male or female operators and whether they had participated in a personal space measurement experiment with a robot that we conducted.
In the post-measurement questionnaire, participants answer questions regarding their feelings toward the robot and whether they felt that the robot moved by voice recognition in order to evaluate whether the instructions were successful. Table 1 shows the fields of the post-measurement questionnaire. Note that Q1 through Q7 are evaluated on a scale of 1 through 7, with 1 meaning strongly disagree and 7 meaning strongly agree. Q8 is answered on a scale of 1 through 7, with 1 meaning very masculine and 7 meaning very feminine.
In the post-experiment questionnaire, participants answer a KiSS-18 and questions regarding their familiarity with the Meccanoid G15KS. KiSS-18 is Kikuchi’s 18-field questionnaire created to measure how much one has mastered social skills required for young people [12]. Social skills are defined here as skills helpful in carrying out smooth interpersonal relationships. In this experiment, a higher total score on the 18 questions demonstrates that the participant has greater communication skills. Note that the average score for male university students is 56.40 points, and the average score for female university students is 58.35 points [12].
3.4 Experimental Procedure
The experiment is conducted with undergraduate and graduate students of Doshisha University, with 13 males and 13 females for a total of 26 participants. One male and one female participants answer Q1 (Did you feel the robot was controlled by voice operation?/Did you feel the robot was controlled by the operator?) of the post-measurement questionnaire with low scores of 1 or 2. For this reason, it is likely that these participants interpret the instructions differently from other participants, and therefore they are excluded from the experiment results analysis.
Figure 4 shows the experimental procedure. In the pre-briefing, the experimenter explains the content of the experiment to the participant in detail and gains their consent to have them answer questionnaires and to release the results in a manner that will not reveal their identities. After the pre-briefing, the participant answers a pre-experiment questionnaire.
Experimental procedure.
Before measuring personal space with the different conditions, we conducted two practice rounds for the purpose of teaching the participant how personal space is measured and to show that the robot is operated by voice recognition (in the no operator condition) or that the robot is controlled by an operator (in the male/female operator conditions). Note that, to counteract any order effect, we change the measuring order of the three conditions (no operator, male operator, and female operator conditions) for each participant. After the practice rounds, we conduct the personal space measurements. Also note that, as the stop-distance method is used for measuring, the participant is instructed to say “stop” when they felt uncomfortable and does not want the robot to approach any further. The participant is also instructed to sit with his/her back touching the chair and to avoid moving his/her head as much as possible during the measuring process to avoid any changes to personal space due to the participant’s head moving. After personal space is measured, the participant answers a post-measurement questionnaire.
At the end of the experiment, the participant answers a post-experiment questionnaire.
4 Experimental Results
4.1 Results of All Participants
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Results of Personal Space Distance
The t-test is applied for the results of the personal space distance statistically. The Bon-ferroni correction is applied to adjust p-values. Figure 5 shows the average and standard deviation of personal space distance for each time measurements are taken for all participants. There is a tendency for the personal space distance to grow the more measurements are taken, and a statistically significant trend is observed between the first measurement and the third. Lauckner et al. indicated that the minimum distance appeared decrease with the repetition [7]. However, this tendency is not seen in this experiment. Many participants reported that they felt negative feelings toward the robot’s appearance. These results suggest that the more measurements are taken, the more participants feel negatively toward the robot, leading to greater personal space distances.
Average and standard deviation of personal space distance for measurement orders (all participants).
Figure 6 shows the average and standard deviation of personal space distances of all participants for each condition. No noteworthy differences between the conditions are present, and no statistically significant differences are observed. Some participants reported in the no operator condition in which they were told that the robot stopped via voice recognition that they did not feel particularly uncomfortable with the robot approaching them because they could control the robot themselves. However, other participants reported that they felt uncertain that the robot would truly stop via voice recognition. Additionally, in the male/female operator conditions in which participants were told an operator would stop the robot, some participants reported that they felt comfortable with the fact that the robot did not stop automatically and was controlled by a person, while other participants felt uncertain that the operator was controlling the robot correctly. These results suggest that personal space distances with robots does not consistently decrease with a certain condition for all participants and that the influence the presence or absence of an operator has on personal space distances may differ with each individual.
Average and standard deviation of personal space distance for each condition (all participants).
Figure 7 shows the average and standard deviation of personal space distances of participants, categorized by their scores on Q7 of the post-measurement questionnaire (Did you feel discomfort to the robot?). Note that there is high evaluation value group of discomfort with a score of 5 or higher and a low evaluation value group of discomfort with a score of 3 or lower. The high evaluation value group of discomfort has a greater personal space distance than the low evaluation value group of discomfort and there is a statistically significant difference between them. These results show that personal space distances increase when participants feel uncomfortable with the robot, regardless of the presence or absence of an operator.
Average and standard deviation of personal space distance categorized by the evaluation value of questionnaire Q7 after measurement.
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Results of Questionnaire
The Wilcoxon signed-rank test is applied for results of all questionnaires statistically. The Bon-ferroni correction is applied to adjust p-values. Figure 8 shows the post-measurement questionnaire results for all of the participants. For Q4 (Did you feel autonomy in the robot?), the no operator condition scores higher than the male/female operator conditions and there is a statistically significant difference between them. For Q5 (Did you feel a sense of reliability for the robot?), the male/female operator conditions score lower levels of discomfort than the no operator condition, and a statistically significant difference is observed between the no operator condition and the female operator condition. The results of Q5 and Q7 suggest that the presence of an operator may lead to more positive feelings toward the robot.
Result of post-measurement questionnaire (all participants).
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Results of Relationship Between Questionnaire Answers and Personal Space Distance
Figure 9 shows a scatter diagram of the answer to post-measurement questionnaire Q5 (Did you feel a sense of reliability for the robot?) and the personal space distance of all participants for the no operator condition. The plot shows a weak negative correlation between Q5 of the post-measurement questionnaire and personal space distance for the no operator condition. More specifically, these results demonstrate a relationship in which those who feel comfortable with an operator-less robot have shorter personal space distances. Below we will focus on the correlations between the post-measurement questionnaire answers and personal space distance for each condition.
Scatter diagram of “answer to post-measurement questionnaire Q5” and “personal space distance” for no operator condition (all participants).
Table 2 shows the correlation between each post-measurement questionnaire answer and personal space distance for all participants. The symbol ○ denotes a weak correlation (R < −0.2, R > 0.2), the symbol ◎ denotes a moderate correlation (R < −0.4, R > 0.4), and the symbol ☆ denotes a strong correlation (R < −0.7, R > 0.7). Red indicates a positive correlation, while blue indicates a negative one. The total of the score of Q5, the score of Q6, and the reverse score of Q7 are defined as the degree of positive feelings toward the robot, and we use this to test the relationship between positive feelings and personal space distances. In this experiment, a relationship is observed in which the more positive the feelings toward the robot, the smaller the personal space distance, regardless of the presence or absence of an operator. In addition, the same tendency is observed for the no operator and male operator conditions.
Next, Fig. 10 shows a scatter diagram of the KiSS-18 score and personal space distance in the no operator condition for all participants. No correlation is observed between communication skill and personal space distance. Moreover, no correlation is observed between KiSS-18 score and personal space distance in the male/female operator conditions.
Scatter diagram of “KiSS-18 score” and “personal space distance” for no operator condition (all participants).
4.2 Results Categorized by Participant Gender
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Results of Personal Space Distance
Figure 11 shows the average and standard deviation of personal space distance of all conditions for participants, categorized by gender. Female participants display a smaller personal space distance than male participants, and a statistically significant difference is present. Likewise, Shibuya’s research results show that women have smaller personal spaces with people [3]. Other prior research results also show similar tendencies in which women have smaller personal spaces with robots [13].
Average and standard deviation of personal space distance for all conditions (male and female participants).
Figure 12 shows the average and standard deviation of personal space distance for each time measurement taken for the participants, categorized by gender. Both male and female participants show a tendency for greater personal space distances each time measurements are re-taken. In addition, female participants display shorter personal space distances than male participants each time measurements are taken, showing statistically significant differences.
Average and standard deviation of personal space distance for measurement orders (male and female participants).
Figure 13 shows the average and standard deviation of personal space distance for each condition for participants, categorized by gender. Female participants display shorter personal space distances than male participants for every condition and show statistically significant differences. Additionally, in the no operator and the male operator conditions, a statistically significant difference is observed between the average personal space distances of male participants and female participants with a 5% level of significance. On the other hand, in the female operator condition, a statistically significant difference of a 1% level of significance is observed between the average personal space distances of male participants and female participants.
Average and standard deviation of personal space distance for each condition (male and female participants).
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Results of Questionnaire
Figure 14 shows the answer results from the post-measurement questionnaire of the participants, categorized by gender. In Q4 of the post-measurement questionnaire (Did you feel autonomy in the robot?), male participants sense more autonomy within the no operator condition than the female operator condition, and there is a statistically significant trend. In sensory evaluation to the robot for each condition, there are no notable differences between male participants and female participants.
Result of post-measurement questionnaire (left: male participants, right: female participants).
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Results of Relationship Between Questionnaire Answers and Personal Space Distance
Table 3 shows a list of correlations between each post-measurement questionnaire answer and personal space distance of participants, categorized by gender. In Q8 of the post-measurement questionnaire (Did you feel masculine/feminine on the robot?), male participants show no correlations in any condition. However, female participants display a relationship in which personal space distances became shorter the more they feel the robot as feminine in the no operator and female operator conditions. Additionally, in Q2 of the post-measurement questionnaire (Did you feel that the robot was physical avatar of the operator?), female participants display a relationship in which personal space distances become shorter the more they feel the robot is physical avatar of the operator in the female operator condition. These results possibly suggest that in the female operator condition, if female participants feel that the robot is physical avatar of the female operator, they feel the robot is of the same gender, therefore resulting in smaller personal space distances.
Table 4 shows a list of correlations between KiSS-18 score and personal space distance for each condition, categorized by gender. Male participants show no relationship between KiSS-18 score and personal space distance. Female participants, however, show a weak negative correlation between KiSS-18 score and personal space distance in the no operator condition. In other words, a relationship is observed in which higher communication skill leads to shorter personal space distance.
4.3 Results Categorized by Participants’ Communication Skills
Next, we test the results by categorizing participants by their KiSS-18 scores. In this experiment, male participants who score higher than the male university student average of 56.40 points and female participants who score higher than the female university student average of 58.35 points are categorized into the high score group of KiSS-18; those who score lower are categorized into the low score group of KiSS-18. Note that after this categorizing, the high score group of KiSS-18 consists of 11 people, while the low score group of KiSS-18 consists of 13 people.
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Results of Personal Space Distance
Figure 15 shows average and standard deviation of personal space distance for all conditions categorized by KiSS-18 score. While the low score group of KiSS-18 display shorter personal space distances than the high score group of KiSS-18, no statistically significant difference is present.
Average and standard deviation of personal space distance for all conditions (high and low score group of KiSS-18).
Figure 16 shows average and standard deviation of personal space distance for each condition, categorized by KiSS-18 score. There are no notable differences between each condition, and no statistically significant differences are observed. No statistically significant differences are observed between the high score group of KiSS-18 and the low score group of KiSS-18 either.
Average and standard deviation of personal space distance for each condition (high and low score group of KiSS-18).
In addition, no notable differences or statistically significant differences are observed between the high score group of KiSS-18 and the low score group of KiSS-18 for average distance measurements, categorized by KiSS-18 score.
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Results of Questionnaire
In post-measurement questionnaire answer results, categorized by KiSS-18 scores, no statistically significant differences are observed between the high score group of KiSS-18 and the low score group of KiSS-18 or between conditions.
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Results of Relationship Between Questionnaire Answers and Personal Space Distance
Table 5 shows a list of correlations between post-measurement questionnaire answer and personal space distance, categorized by KiSS-18 scores. The low score group of KiSS-18 shows more strong positive correlations than the high score group of KiSS-18.
Table 6 shows a list of correlations between KiSS-18 score and personal space distance for each condition, categorized by KiSS-18 scores. The low score group of KiSS-18 shows moderate negative and weak negative correlations between KiSS-18 score and personal space distance in the no operator and female operator conditions. These results indicate that a relationship is observed in the low score group of KiSS-18 in which greater communication skill leads to shorter personal space distance. The high score group of KiSS-18, on the other hand, shows a weak positive correlation between KiSS-18 score and personal space distance in the female operator condition.
5 Conclusion
In this study, we aim to investigate the influences the presence and absence an operator of a humanoid robot has on personal space by measuring personal space in three conditions: a no operator condition, a male operator condition, and a female operator condition. The results of the experiment show no notable differences of average personal space distances among the conditions, with no statistically significant differences. These results suggest that personal space distances with robots do not consistently decrease with a certain condition for all participants, and that the influence the presence or absence of an operator has on personal space distances with the robot may differ with each individual. However, personal space distances increase for those who feel uncomfortable with the robot, regardless of the presence or absence of an operator. Moreover, a certain correlation is observed between personal space distance and participant’s communication skill and sensory evaluation to the robot, and it is especially clear that positive feelings toward the robot have great influence. In addition, many participants commented that they were more aware of the robot’s presence and appearance than the presence of the operator. Yamaoka et al. also report that people’s behavior toward a robot does not change with the presence or absence of an operator when they are more aware of the robot than the operator [14]. In other words, factors having to do with the robot, such as the non-verbal information that it exhibits, may have a great influence on people’s personal space, to a greater extent than the presence or absence an operator may have. These results suggest that an individual’s communication skill and sensory evaluation to the robot may possibly have a greater influence on personal space than the presence or absence of an operator.
We conduct investigating in this study not by focusing on the influence of the robot itself, but by focusing on an external factor: the operator. It may be necessary for further studies to investigate the influences that the robot itself has on personal space. In particular, it may be possible to consistently alter personal space by focusing on the non-verbal information that the robot exhibits and by controlling people’s sensory evaluation to the robot.
References
Kanda, T., Ishiguro, H., Ono, T., Imai, M., Nakatsu, R.: An evaluation on interaction between humans and an autonomous robot Robovie. J. Robot. Soc. Jpn. 20(3), 315–323 (2002)
Kashiwabara, T., Osawa, H., Shinozawa, K., Imai, M.: TEROOS: a wearable avatar to enhance joint activities. In: CHI 2012 Proceeding of the SIGCHI Conference on Human Factors in Computing Systems, pp. 2001–2004 (2012)
Shibuya, S.: A study of the shape of personal space. Bull. Yamanashi Med. Univ. 2, 41–49 (1985)
Hall, E.T.: The Hidden Dimension. Doubleday, New York (1966)
Fujihara, T.: The study of psychological distance reflected as personal space. Memoirs of the Faculty of Integrated Arts and Sciences. III. Stud. Inf. Behav. Sci. 10, 83–92 (1987)
Yasumoto, M., Kamide, H., Mae, Y., Ohara, K., Takubo, T., Arai, T.: Personal space for the humanoid robot and a presentation method. In: JSME Annual Conference on Robotics and Mechatronics (Robomec), pp. 2A2-D18(1)–2A2-D18(4) (2010)
Lauckner, M., Kobiela, F., Manzey, D.: ‘Hey robot, please step back!’ - exploration of a spatial threshold of comfort for human-mechanoid spatial interaction in a hallway scenario. In: 23rd IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN), pp. 780–787 (2014)
James, W., Imada, H.: Psychology, vol. 1, pp. 245–301. Iwanami Shoten, Tokyo (1992)
Ariga, A.: Expansive personal space: distance between personal belongings reflects the interpersonal distance of their owners. Jpn. J. Psychol. 87(2), 186–190 (2016)
Fujita, Y.: Design and development for personal robot “PaPeRo”. J. Soc. Instrum. Control Eng. 42(6), 521–526 (2003)
Fraser, N., Gilbert, G.: Simulating speech systems. Comput. Speech Lang. 5(1), 81–99 (1991)
Hori, H., Yoshida, H.: Psychological Measurement Scale Collection II, pp. 170–172. Saiensu-sha, Tokyo (2001)
Tatsumi, A., Matsushima, T., Okubo, M.: Influence of humanoid robot’s behavior on personal space. In: 2018 Asian Conference on Design and Digital Engineering (ACDDE 2018) (2018)
Yamaoka, F., Kanda, T., Ishiguro, H., Hagita, N.: Interacting with a human or a humanoid robot? IPSJ J. 48(11), 3577–3587 (2007)
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This work was supported by JSPS KAKENHI Grant Number 18K11414.
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Tatsumi, A., Okubo, M. (2019). Influence of Presence of Operator of Humanoid Robot on Personal Space. In: Kurosu, M. (eds) Human-Computer Interaction. Perspectives on Design. HCII 2019. Lecture Notes in Computer Science(), vol 11566. Springer, Cham. https://doi.org/10.1007/978-3-030-22646-6_25
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