Background Embodied conversational agents (ECAs) are animated computer characters that simulate face-to-face counseling. Owing to their capacity to establish and maintain an empathic relationship, they are deemed to be a promising tool for starting and maintaining a healthy lifestyle. Objective This review aimed to identify the current practices in designing and evaluating ECAs for coaching people in a healthy lifestyle and provide an overview of their efficacy (on behavioral, knowledge, and motivational parameters) and use (on usability, usage, and user satisfaction parameters). Methods We used the Arksey and O’Malley framework to conduct a scoping review. PsycINFO, Medical Literature Analysis and Retrieval System Online, and Scopus were searched with a combination of terms related to ECA and lifestyle. Initially, 1789 unique studies were identified; 20 studies were included. Results Most often, ECAs targeted physical activity (n=16) and had the appearance of a middle-aged African American woman (n=13). Multiple behavior change techniques (median=3) and theories or principles (median=3) were applied, but their interpretation and application were usually not reported. ECAs seemed to be designed for the end user rather than with the end user. Stakeholders were usually not involved. A total of 7 out of 15 studies reported better efficacy outcomes for the intervention group, and 5 out of 8 studies reported better use-related outcomes, as compared with the control group. Conclusions ECAs are a promising tool for persuasive communication in the health domain. This review provided valuable insights into the current developmental processes, and it recommends the use of human-centered, stakeholder-inclusive design approaches, along with reporting on the design activities in a systematic and comprehensive manner. The gaps in knowledge were identified on the working mechanisms of intervention components and the right timing and frequency of coaching.

No abstract

Embodied conversational agents may be used to engage users in adopting eHealth applications. The aim of this research is to investigate which design features establish a positive first impression of an agent in this context. A set of eight static agent images, different in age, gender and role, were subjected to testing in an online questionnaire. Respondents (n = 155) selected their preferred design and rated the characteristicsfriendliness, expertise, reliability, involvement and authorityand the likeliness of following the agent's advice for all designs. In addition, focus groups (n = 13) were conducted for detailed understandings supporting these impressions. Our results show that, for both a general and elderly population, (1) people seem to prefer images of young, female agents over old, male agents, (2) the (a) age, (b) gender and (c) role of the agent image affect the perception of the agent's characteristics and the likeliness of following the agent's advice, and that (3) both the general and elderly population prefer an agent image that is similar in (a) age and (b) gender. A next step would be to investigate how the characteristics of the agent designs are perceived after interaction with the agent.

Background Embodied conversational agents (ECAs) have great potential for health apps but are rarely investigated as part of such apps. To promote the uptake of health apps, we need to understand how the design of ECAs can influence the preferences, motivation, and behavior of users. Objective This is one of the first studies that investigates how the appearance of an ECA implemented within a health app affects users’ likeliness of following agent advice, their perception of agent characteristics, and their feeling of rapport. In addition, we assessed usability and intention to use. Methods The ECA was implemented within a frailty assessment app in which three health questionnaires were translated into agent dialogues. In a within-subject experiment, questionnaire dialogues were randomly offered by a young female agent or an older male agent. Participants were asked to think aloud during interaction. Afterward, they rated the likeliness of following the agent’s advice, agent characteristics, rapport, usability, and intention to use and participated in a semistructured interview. Results A total of 20 older adults (72.2 [SD 3.5] years) participated. The older male agent was perceived as more authoritative than the young female agent (P=.03), but no other differences were found. The app scored high on usability (median 6.1) and intention to use (median 6.0). Participants indicated they did not see an added value of the agent to the health app. Conclusions Agent age and gender little influence users’ impressions after short interaction but remain important at first glance to lower the threshold to interact with the agent. Thus, it is important to take the design of ECAs into account when implementing them into health apps.

Background Embodied conversational agents (ECAs) have the potential to stimulate actual use of eHealth apps. An ECA’s design influences the user’s perception during short interactions, but daily life evaluations of ECAs in health care are scarce. Objective This is an exploratory, long-term study on the design of ECAs for eHealth. The study investigates how patients perceive the design of the ECA over time with regard to the ECA’s characteristics (friendliness, trustworthiness, involvement, expertise, and authority), small talk interaction, and likeliness of following the agent’s advice. Methods We developed an ECA within an eHealth self-management intervention for patients with both chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF), which we offered for 4 months. Patients rated 5 agent characteristics and likeliness of following the agent’s advice before use and after 3 and 9 weeks of use. The amount of patients’ small talk interaction was assessed by log data. Lastly, individual semistructured interviews were used to triangulate results. Results Eleven patients (7 male and 4 female) with COPD and CHF participated (median age 70 years). Patients’ perceptions of the agent characteristics did not change over time (P>.05 for all characteristics) and only 1 participant finished all small talk dialogues. After 3 weeks of use, the patients were less likely to follow the agent’s advice (P=.01). The agent’s messages were perceived as nonpersonalized and the feedback as inappropriate, affecting the agent’s perceived reliability. Conclusions This exploratory study provides first insights into ECA design for eHealth. The first impression of an ECA’s design seems to remain during long-term use. To investigate future added value of ECAs in eHealth, perceived reliability should be improved by managing users’ expectations of the ECA’s capabilities and creating ECA designs fitting individual needs. Trial Registration Netherlands Trial Register NL6480; https://www.trialregister.nl/trial/6480

No abstract

Welcome! Nice to meet you, my name is Sylvia. I will be guiding you throughout this thesis. I will provide you with a quick summary at the beginning of every chapter. I must say, I found it very interesting. I hope you enjoy reading it too. See you soon! vi CONTENTS 01 General Introduction 02 Design Features of Embodied Conversational Agents (ECAs) in eHealth: a Literature Review

No abstract