• Educational Technology International
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• v.19 no.1
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• pp.61-91
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• 2018

The animated pedagogical agent has been implemented to promote learning outcomes and motivation in multimedia learning. It has been claimed that one of the advantages of using pedagogical agent is persona effect - the personalization or social presence of pedagogical agent can enhance learning engagement and motivation. However, prior research is inconclusive as to whether and how the features of the pedagogical agent have effects on the persona effect. This study investigated whether the similarity between a pedagogical agent and the real instructor in terms of the voice and outlook would improve students' perception of the agent's persona. The study also examined the effect by the size of pedagogical agent on the persona perception. Two experiments were conducted with a total of 115 college students. Experiment 1 indicated a significant main effect of voice on the persona perception. Experiment 2 was conducted to examine whether the size of pedagogical agent would affect the voice effect on the persona perception. The results showed that the instructor-like voice yielded higher persona perception regardless of the pedagogical agent's size. Overall, the study findings indicated that the similarity in voice positively fostered the agent's persona.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.573-585
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• 2018

Services for navigation and entertainment through AI-based voice user interface devices are becoming popular in the connected car system. Given the classification of VUI agent developers as IT companies and automakers, this study explores attributes of agent persona and user experience that impact the driver's perceived safety and satisfaction. Participants of a car simulator experiment performed entertainment and navigation tasks, and evaluated the perceived safety and satisfaction. Results of regression analysis showed that credibility of the agent developer, warmth and attractiveness of agent persona, and efficiency and care of the UX dimension showed significant impact on the perceived safety. The determinants of perceived satisfaction were unity of auto-agent makers and gender as predisposing factors, distance in the agent persona, and convenience, efficiency, ease of use, and care in the UX dimension. The contributions of this study lie in the discovery of the factors required for developing conversational VUI into the autonomous driving environment.

• Science of Emotion and Sensibility
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• v.15 no.1
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• pp.47-56
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• 2012

The purpose of this study is to test the effect of pedagogical agent realism and expertise on persona effect. There were two perspectives of the pedagogical agents' social interaction. Self-identification hypothesis argues that complexity of agent image is better to increase social interaction. Subjective identification insists that simplified image is more helpful to facilitate social interaction. However, from the cognitive load theory perspective, learners' expertise can be a major factor to determine persona effect. Sixty-eight college students (male=19 and female=49) participated. The independent variables were the degree of realism of pedagogical agent (detailed vs. simplified image) and the expertise (high prior knowledge group vs. low prior knowledge group). The dependant variables were comprehension test and the agent persona instrument (API). There was no significant difference in comprehension test score; however, there were significant interaction effect on the most constructs of API: 1) facilitating of learning, 2) credible, and 3) human-like. The follow-up analysis of simple main effect revealed that high expertise group showed significantly higher perception of the three construct with high realism of pedagogical agent. The results of study show that learners' expertise plays a key role of perception of persona effect.

• Science of Emotion and Sensibility
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• v.16 no.3
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• pp.281-292
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• 2013

The purpose of this study was to identify the effect of gesture and facial expression on persona effects. Fifty-six college students were recruited for this study, and non-verbal communication skills were applied to a pedagogical agent with gesture (conversational vs. deictic) and facial expression. The conversational gesture may have relationship with social interaction hypothesis of pedagogical agent while the deictic gesture may have relationship with attentional guidance hypothesis. The facial expression can be assumed to facilitate the social interaction between the pedagogical agent and learners. Interestingly, the conversational gesture group showed a tendency of outperforming the deictic gesture group. It may imply that the social interaction theory has a strong impact on cognitive support as well as social interaction for learners. There was a significant interaction effect on the engagement when both of facial expression and conversational gesture were applied. This result has two implications. First, facial expression can facilitate the persona effect for engagement.

• The Journal of Korean Association of Computer Education
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• v.15 no.1
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• pp.55-64
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• 2012

The purpose of this study is to identify how realism of pedagogical agent can have impacts on persona effect and cognitive load factors. Eighty-two college students participated, and the independent variables of this study were the degree of image details and presence of gesture. The degree of image details were picture, illustration, and line-drawing. The $3{\times}2$ factorial design was applied. There was a significant interaction effect on the engaging of agent persona instrument. When the learners were under the condition of line-drawing agent without gesture, they showed the highest score on engaging of the agent persona instrument. Regarding the cognitive load factors, when learners under the condition of line-drawing showed the highest score of self-evaluation.

• Journal of the HCI Society of Korea
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• v.12 no.4
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• pp.45-55
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• 2017

In recent years, some service providers have introduced chatbot agents to provide engagement in the healthcare field. However, current research on chatbot agents is still limited to designing various chatbot identities for healthcare services. By contrast, this study aims to investigate how various agent identities affect users' perceptions and behaviors differently. We developed three chatbot agents with different identities: a doctor (an individual), a hospital (an institution), and a virtual agent (a machine). Then, we recruited 36 users and divided them into three groups, each using a different chatbot agent. They were asked to track their behaviors and review advice from the chatbot agent for six days. Post-hoc surveys and interviews were conducted in order to investigate users' perceptions. The findings are as follows: participants felt more trusting and intimate with the doctor and hospital agents than with the virtual agent. Many of the participants preferred the hospital agent due to its higher reliability. However, all three agents did not lead the participants to change their behaviors. This study contributes to providing practical guidelines for designing chatbots in the healthcare field by studying users' perceptions and behaviors depending on chatbot identities.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.76-82
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• 1978

In order to study the change of laboratory parameters of lead poisoning, 8 persona who had not been treated previously for lead poisoning (Group 1 and 6 persons who had been inadequately treated for few months for chronic lead poisoning at local clinic (Group 2) were examined. They had occupational exposure to lead for 3 to 18 years (mean, 7.6). In group 1 blood lead, urine lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels before our treatment exceeded the critical levels of lead poisoning. In group 2 urine lead level exceeded but blood lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels were within normal limits. All of them were treated with D-penicillamine for 4 months as inpatients at Industrial Accident Hospital. The dose of D-penicillamine was the same in all patients; 600 mg per day p.o. and the chelating agent was administer every other week. For laboratory analysis, 24 hour urine and 10 gm of whole blood were collected every 1 month on last day of non-administration period. The results were as follows: 1. It was found that urine lead level was decreased below the cirtical level of lead poisoning after 4 month's treatment with D-penicillamine and blood lead level was decreased more progressively below the critical level after 1 month treatment. 2. Urine coproporphyrin and ${\delta}$-aminolevulinic acid levels were decreased progressively to normal range after 1 month treatment. 3. Two months after treatment, blood lead, urine lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels showed some increasing trends. 4. Urine lead level should be checked in a person who had been inadequately treated with chelating agents because blood lead, coproporphyrin and ${\delta}$-aminolevulinic acid might be in normal range.