{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/125160"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/125160","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Effects of Human Emotions, Robot Reliability, and Team Hierarchy on Human-Robot Interaction","abstract":"Social robots gradually become a vital part of human lives as they can assist humans in complex tasks. To enhance the effectiveness and user acceptance of human-robot interaction (HRI), it is critical to understand what factors could improve human trust in robots. This dissertation builds on an existing framework of human-related, robot-related, and environmental factors in human-robot trust. Emotions, a human-related factor, have been discovered to have critical impacts on HRI, but research has focused more on robots' emotional expressions than user emotions. To bridge this research gap, three human-centered studies were conducted in the present dissertation investigating the impact of users' emotions (happiness and anger) along with robot reliability (robot-related) and team hierarchy (environmental factor) on their trust toward robots in a collaborative setting, an escape room, with a social robot, Pepper. Additionally, user perceptions, perceived workload, and task performance were also measured in the dissertation. The experimental setting and procedures for the three studies were similar. To induce participants' emotions, they were asked to write down their emotional experiences regarding the assigned emotions (anger vs. happiness) for 12 minutes, then solve puzzles in an escape room with Pepper. An emotional manipulation check was completed by the participants by filling out an emotional evaluation survey three times: before the induction, after the induction, and after the completion of the escape room. In addition, user perceptions, trust, perceived workload, and task performance were also collected through validated questionnaires and observations. Study I focused only on the effect of human emotions, anger and happiness (N = 46), suggesting that happy participants rated the robot agent as significantly more likable, safer, and more comfortable, while angry participants complied significantly but fewer succeeded. Among those who failed, angry participants showed higher cognitive trust in the robot. Study II (N = 86) explored emotion and robot reliability (high vs. low) with a between-subjects design. Happy participants rated the robot as more anthropomorphized, intelligent, and likable, with higher trust. Participants in the high-reliability condition perceived better performance, complied more, and responded faster than the participants in the low-reliability condition. Study III (N = 52) investigated emotion and team hierarchy (human-follower-robot-leader vs. human-leader-robot-follower) with a mixed-subjects design. Participants in the follower role perceived the robot as less responsive but complied more. Angry participants perceived the robot as more capable of constructive responses than happy participants while happy participants showed significantly more verbal interactions with the robot. An interaction between emotion and hierarchy was shown for social presence and perceived performance. Interviews highlighted the role of emotions and hierarchy in user perception, decision-making, emotional changes, and responsibility for team success or failure. In conclusion, the results underscored the importance of user emotions, robot reliability, and team hierarchy in shaping user perceptions and trust in robots and task performance, providing valuable theoretical and practical implications for emotions in HRI.","abstract_html":"Social robots gradually become a vital part of human lives as they can assist humans in complex tasks. To enhance the effectiveness and user acceptance of human-robot interaction (HRI), it is critical to understand what factors could improve human trust in robots. This dissertation builds on an existing framework of human-related, robot-related, and environmental factors in human-robot trust. Emotions, a human-related factor, have been discovered to have critical impacts on HRI, but research has focused more on robots' emotional expressions than user emotions. To bridge this research gap, three human-centered studies were conducted in the present dissertation investigating the impact of users' emotions (happiness and anger) along with robot reliability (robot-related) and team hierarchy (environmental factor) on their trust toward robots in a collaborative setting, an escape room, with a social robot, Pepper. Additionally, user perceptions, perceived workload, and task performance were also measured in the dissertation. The experimental setting and procedures for the three studies were similar. To induce participants' emotions, they were asked to write down their emotional experiences regarding the assigned emotions (anger vs. happiness) for 12 minutes, then solve puzzles in an escape room with Pepper. An emotional manipulation check was completed by the participants by filling out an emotional evaluation survey three times: before the induction, after the induction, and after the completion of the escape room. In addition, user perceptions, trust, perceived workload, and task performance were also collected through validated questionnaires and observations. Study I focused only on the effect of human emotions, anger and happiness (N = 46), suggesting that happy participants rated the robot agent as significantly more likable, safer, and more comfortable, while angry participants complied significantly but fewer succeeded. Among those who failed, angry participants showed higher cognitive trust in the robot. Study II (N = 86) explored emotion and robot reliability (high vs. low) with a between-subjects design. Happy participants rated the robot as more anthropomorphized, intelligent, and likable, with higher trust. Participants in the high-reliability condition perceived better performance, complied more, and responded faster than the participants in the low-reliability condition. Study III (N = 52) investigated emotion and team hierarchy (human-follower-robot-leader vs. human-leader-robot-follower) with a mixed-subjects design. Participants in the follower role perceived the robot as less responsive but complied more. Angry participants perceived the robot as more capable of constructive responses than happy participants while happy participants showed significantly more verbal interactions with the robot. An interaction between emotion and hierarchy was shown for social presence and perceived performance. Interviews highlighted the role of emotions and hierarchy in user perception, decision-making, emotional changes, and responsibility for team success or failure. In conclusion, the results underscored the importance of user emotions, robot reliability, and team hierarchy in shaping user perceptions and trust in robots and task performance, providing valuable theoretical and practical implications for emotions in HRI.","abstract_has_math":false,"creators":["Dong, Jiayuan"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Industrial and Systems Engineering","degree_department":"Industrial and Systems Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Jeon, Myounghoon"],"committee_members":["Lim, Sol Ie","Lau, Nathan Ka Ching","Sabanovic, Selma"],"year":2025,"date_issued":"2025-04-09","date_published":"2025-04-09","updated_at":"2026-07-22T22:20:12Z","subjects":["Human-Robot Interaction","Emotion","Robot Reliability","Team Hierarchy","User Experience","Trust in HRI"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:42872"],"render_values":[{"text":"vt_gsexam:42872","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/125160","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Jeon, Myounghoon"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Lim, Sol Ie","Lau, Nathan Ka Ching","Sabanovic, Selma"]},{"key":"dc:contributor.department","label":"Department","values":["Industrial and Systems Engineering"]},{"key":"dc:creator","label":"Author","values":["Dong, Jiayuan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-04-10T08:00:17Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-04-10T08:00:17Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-04-09"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Industrial and Systems Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Human-Robot Interaction","Emotion","Robot Reliability","Team Hierarchy","User Experience","Trust in HRI"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:42872"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/125160"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Social robots gradually become a vital part of human lives as they can assist humans in complex tasks. To enhance the effectiveness and user acceptance of human-robot interaction (HRI), it is critical to understand what factors could improve human trust in robots. This dissertation builds on an existing framework of human-related, robot-related, and environmental factors in human-robot trust. Emotions, a human-related factor, have been discovered to have critical impacts on HRI, but research has focused more on robots' emotional expressions than user emotions. To bridge this research gap, three human-centered studies were conducted in the present dissertation investigating the impact of users' emotions (happiness and anger) along with robot reliability (robot-related) and team hierarchy (environmental factor) on their trust toward robots in a collaborative setting, an escape room, with a social robot, Pepper. Additionally, user perceptions, perceived workload, and task performance were also measured in the dissertation. The experimental setting and procedures for the three studies were similar. To induce participants' emotions, they were asked to write down their emotional experiences regarding the assigned emotions (anger vs. happiness) for 12 minutes, then solve puzzles in an escape room with Pepper. An emotional manipulation check was completed by the participants by filling out an emotional evaluation survey three times: before the induction, after the induction, and after the completion of the escape room. In addition, user perceptions, trust, perceived workload, and task performance were also collected through validated questionnaires and observations. Study I focused only on the effect of human emotions, anger and happiness (N = 46), suggesting that happy participants rated the robot agent as significantly more likable, safer, and more comfortable, while angry participants complied significantly but fewer succeeded. Among those who failed, angry participants showed higher cognitive trust in the robot. Study II (N = 86) explored emotion and robot reliability (high vs. low) with a between-subjects design. Happy participants rated the robot as more anthropomorphized, intelligent, and likable, with higher trust. Participants in the high-reliability condition perceived better performance, complied more, and responded faster than the participants in the low-reliability condition. Study III (N = 52) investigated emotion and team hierarchy (human-follower-robot-leader vs. human-leader-robot-follower) with a mixed-subjects design. Participants in the follower role perceived the robot as less responsive but complied more. Angry participants perceived the robot as more capable of constructive responses than happy participants while happy participants showed significantly more verbal interactions with the robot. An interaction between emotion and hierarchy was shown for social presence and perceived performance. Interviews highlighted the role of emotions and hierarchy in user perception, decision-making, emotional changes, and responsibility for team success or failure. In conclusion, the results underscored the importance of user emotions, robot reliability, and team hierarchy in shaping user perceptions and trust in robots and task performance, providing valuable theoretical and practical implications for emotions in HRI."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["The fast advancement of social robots becoming an important part of daily life, benefiting humans in diverse environments, ranging from healthcare to education and entertainment. As these robots assist and collaborate with us, it is essential to understand how to build trust between humans and robots to ensure effective interactions. This dissertation explores how human emotions (happiness and anger), robot reliability, and team hierarchy impact trust in robots, as well as how these factors influence user perceptions, workload, and task performance. Three experiments were conducted in an escape room setting, where participants worked with a social robot, Pepper, to solve puzzles. Before the task, participants were asked to recall and write about emotional experiences to induce either anger or happiness. Throughout the experiment, data were collected through surveys, observations, and interviews to understand individuals' trust, perceptions, task success, and emotional responses. The outcome of the three studies revealed that emotions, robot reliability, and team hierarchy influence human-robot interaction. In study I, happy participants found the robot more likable and intelligent, while angry participants were more likely to comply with the robot's instructions but had lower success rates. In study II, when the robot was highly reliable, participants felt that they performed better and showed more trust in the robot. In study III, participants in a follower role complied more but perceived the robot as less responsive. Angry participants viewed the robot as more capable of providing supportive responses, while happy participants engaged in more conversation with the robot. These results highlight the importance of understanding human emotions and team dynamics when designing social robots. By designing robots that can adapt to user emotions and facilitate trust effectively, developers can improve human-robot collaboration in various fields, designing emotion-aware and role-sensitive robots and ensuring smoother and more natural interactions in the future."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Effects of Human Emotions, Robot Reliability, and Team Hierarchy on Human-Robot Interaction"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Jeon, Myounghoon"],"dc:contributor.committeemember":["Lim, Sol Ie","Lau, Nathan Ka Ching","Sabanovic, Selma"],"dc:contributor.department":["Industrial and Systems Engineering"],"dc:creator":["Dong, Jiayuan"],"dc:date.accessioned":["2025-04-10T08:00:17Z"],"dc:date.available":["2025-04-10T08:00:17Z"],"dc:date.issued":["2025-04-09"],"dc:description.abstract":["Social robots gradually become a vital part of human lives as they can assist humans in complex tasks. To enhance the effectiveness and user acceptance of human-robot interaction (HRI), it is critical to understand what factors could improve human trust in robots. This dissertation builds on an existing framework of human-related, robot-related, and environmental factors in human-robot trust. Emotions, a human-related factor, have been discovered to have critical impacts on HRI, but research has focused more on robots' emotional expressions than user emotions. To bridge this research gap, three human-centered studies were conducted in the present dissertation investigating the impact of users' emotions (happiness and anger) along with robot reliability (robot-related) and team hierarchy (environmental factor) on their trust toward robots in a collaborative setting, an escape room, with a social robot, Pepper. Additionally, user perceptions, perceived workload, and task performance were also measured in the dissertation. The experimental setting and procedures for the three studies were similar. To induce participants' emotions, they were asked to write down their emotional experiences regarding the assigned emotions (anger vs. happiness) for 12 minutes, then solve puzzles in an escape room with Pepper. An emotional manipulation check was completed by the participants by filling out an emotional evaluation survey three times: before the induction, after the induction, and after the completion of the escape room. In addition, user perceptions, trust, perceived workload, and task performance were also collected through validated questionnaires and observations. Study I focused only on the effect of human emotions, anger and happiness (N = 46), suggesting that happy participants rated the robot agent as significantly more likable, safer, and more comfortable, while angry participants complied significantly but fewer succeeded. Among those who failed, angry participants showed higher cognitive trust in the robot. Study II (N = 86) explored emotion and robot reliability (high vs. low) with a between-subjects design. Happy participants rated the robot as more anthropomorphized, intelligent, and likable, with higher trust. Participants in the high-reliability condition perceived better performance, complied more, and responded faster than the participants in the low-reliability condition. Study III (N = 52) investigated emotion and team hierarchy (human-follower-robot-leader vs. human-leader-robot-follower) with a mixed-subjects design. Participants in the follower role perceived the robot as less responsive but complied more. Angry participants perceived the robot as more capable of constructive responses than happy participants while happy participants showed significantly more verbal interactions with the robot. An interaction between emotion and hierarchy was shown for social presence and perceived performance. Interviews highlighted the role of emotions and hierarchy in user perception, decision-making, emotional changes, and responsibility for team success or failure. In conclusion, the results underscored the importance of user emotions, robot reliability, and team hierarchy in shaping user perceptions and trust in robots and task performance, providing valuable theoretical and practical implications for emotions in HRI."],"dc:description.abstractgeneral":["The fast advancement of social robots becoming an important part of daily life, benefiting humans in diverse environments, ranging from healthcare to education and entertainment. As these robots assist and collaborate with us, it is essential to understand how to build trust between humans and robots to ensure effective interactions. This dissertation explores how human emotions (happiness and anger), robot reliability, and team hierarchy impact trust in robots, as well as how these factors influence user perceptions, workload, and task performance. Three experiments were conducted in an escape room setting, where participants worked with a social robot, Pepper, to solve puzzles. Before the task, participants were asked to recall and write about emotional experiences to induce either anger or happiness. Throughout the experiment, data were collected through surveys, observations, and interviews to understand individuals' trust, perceptions, task success, and emotional responses. The outcome of the three studies revealed that emotions, robot reliability, and team hierarchy influence human-robot interaction. In study I, happy participants found the robot more likable and intelligent, while angry participants were more likely to comply with the robot's instructions but had lower success rates. In study II, when the robot was highly reliable, participants felt that they performed better and showed more trust in the robot. In study III, participants in a follower role complied more but perceived the robot as less responsive. Angry participants viewed the robot as more capable of providing supportive responses, while happy participants engaged in more conversation with the robot. These results highlight the importance of understanding human emotions and team dynamics when designing social robots. By designing robots that can adapt to user emotions and facilitate trust effectively, developers can improve human-robot collaboration in various fields, designing emotion-aware and role-sensitive robots and ensuring smoother and more natural interactions in the future."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:42872"],"dc:identifier.uri":["https://hdl.handle.net/10919/125160"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Human-Robot Interaction","Emotion","Robot Reliability","Team Hierarchy","User Experience","Trust in HRI"],"dc:title":["Effects of Human Emotions, Robot Reliability, and Team Hierarchy on Human-Robot Interaction"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Industrial and Systems Engineering"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:12Z"}