Smartphone-based conversational agents offer a convenient way to deliver health education, particularly for managing complex health conditions such as chronic diseases. The present study explores using a smartphone-based virtual agent system to aid patients with a chronic heart condition—atrial fibrillation—to manage their health by encouraging the use of a heart rhythm sensor integrated with their smartphones. We report the results of a randomized clinical trial with 240 patients experiencing atrial fibrillation who were provided with smartphones and heart rhythm sensors for 4 months. Participants in the intervention group interacted with a virtual agent, while the control group received general health education via the WebMD app. Intervention participants completed a median 91 interactions with the agent over the 4 months of the study period, and agent features designed to increase engagement–such as storytelling–were effective at increasing use. The agent’s promotion of heart rhythm sensor use was effective, with intervention participants taking significantly more heart rhythm readings compared to those in the control group. Participants were followed for 8 months thereafter to assess the sustainability of the effects, specifically focusing on medication adherence.

Over 55 million adults worldwide have dementia, a syndrome characterized by deterioration in cognitive functioning. Screening for mild cognitive impairment is important to identify dementia early to facilitate diagnosis and initiate treatment that may modify the disease trajectory. However, standard cognitive screening tools are time-consuming, require expert administration, and make people feel as if they are being tested and are thus potentially stigmatizing. Consequently, standard cognitive screening tools are underutilized, and dementia is often identified much later in the disease process leading to greater health-related and societal harms. We explored cognitive ability assessments using virtual agents, in which assessments are made during conversational dialogues. We evaluated four strategies for the assessment of cognitive ability in a sample of 41 individuals with varying cognitive ability, comparing each strategy to scores on the Mini Mental Status Exam (MMSE), the gold standard clinical screening tool for cognitive impairment. One of the four conversational strategies demonstrated significant agreement with the MMSE, with a sensitivity of 92.3% and a specificity of 48.3% for identification of impairment compared to the MMSE. Participants reported moderate levels of satisfaction with the agent-based conversational assessment. This approach could be used to identify individuals warranting more evaluation for possible cognitive impairment.

Client-centered counseling, in which individuals are prompted to talk about their behavior, is the standard treatment for Alcohol misuse. However, open-ended conversations with virtual agent counselor raise potential safety concerns if the agent misunderstands and provides erroneous advice. Thus, while generative machine learning models have been successful for language understanding and generation tasks, these approaches may not be effective or safe for counseling. We present a hybrid dialog system that uses a machine-learning model to generate responses to individual client speech combined with a rule-based approach to transition through structured counseling sessions. The dialog system is used to drive a virtual agent alcohol misuse counselor. We evaluated this hybrid system by comparing it to a functionally equivalent system in which the dialog is driven by fully-constraining user utterances via multiple-choice menus among individuals with problematic drinking. Participants who interacted with the agent using the hybrid dialog system reported a higher degree of readiness to change their drinking habits compared to the system using constrained input. Additionally, the outputs of the models used by the system were judged to be safe and appropriate for the task by expert counselors.

HCI researchers have increasingly examined how social context shapes health behaviors. Much of this work operates at the interpersonal level. Communities such as churches play important roles in supporting wellbeing and addressing health inequities. While some work has investigated creating digital health tools for religious populations, few have explicitly focused on the incorporation of community support in the form of prayer support. Embedding health interventions in any community has the potential to support or challenge the community’s dynamics. We report on findings from interviews with 17 church members who used a church-based mHealth application over a 4-week period and provide guidelines for developers based on these results. Through their use of the system, participants characterized several community dynamics including a desire for social intimacy, communicating care, creating opportunities for fellowship, maintaining privacy and discretion, and building community connections, and how these dynamics influence their aspirations for a church-based health app.

Job advertisements in white male-dominated organizations are often biased in ways that discourage female and minority candidates from applying. We explored the use of a female African American virtual agent who provides a first-person reaction to a biased job advertisement, providing an impassioned, vivid description of her feelings about the advertisement, the position, and the organization offering the job, and how the position---as described---would impact her life were she to take the job. We evaluate the impact interactions with this agent have on the effort study participants invest in editing the job advertisement following their interaction with the agent, compared to reading a page of standard educational text on diversity in hiring. Participants who interacted with the agent spent significantly more effort correcting the job ad, as measured both by the number of edit operations and the number of biased phrases removed, compared to participants in the control condition. Implications and a future research agenda for increasing diversity using virtual agents are presented.

Culturally informed design for virtual agents has been shown to positively impact health outcomes when tailored to target audiences. We present a participatory design methodology for culturally tailoring virtual agents. Investigators worked with key informants from our target population, members of predominantly Black church communities, to design culturally-relevant and sensitive virtual agent health promotion interventions. In the first participatory session, key informants designed agents to assist them with different aspects of their lives, providing input on agent appearance and agent functionality. In a second design session, participants re-wrote the content of a health conversation with an agent, to include personally-relevant content related to their community (e.g., religious and scriptural references). We report design principles for religious tailoring derived from these studies. We conducted a validation study to assess the effects of applying these principles to agents that promoted two health behaviors, finding that participants responded very positively to the tailored agents.

Research on the psychology of humor indicates that humor can increase the impact of persuasive messages in certain circumstances, suggesting that virtual agents could use humor to improve the effectiveness of motivational counseling with users. To explore this idea, we developed two virtual agents that attempt to motivate users to perform healthy behaviors - either to increase exercise or fruit and vegetable consumption - and systematically vary whether they use humor or not in their counseling conversations. Human-authored jokes were selected from a large corpus based on the nature of the humor (empathetic affiliative humor that serves to build relational closeness), health topic relevance, and subjective ratings of funniness, as well as relevance to user stage of behavior change. We evaluated our agents in a two-treatment counterbalanced within-subjects experiment, where participants interacted with a humorous and non-humorous agent motivating either exercise or healthy diet. We found the interaction with the humorous agent led to a significantly greater change in motivation to engage in the target behavior than interacting with the non-humorous agent.

The visual design of virtual agents and scenes presents developers with a plethora of choices. We conducted two studies in which we manipulated the design of a virtual health counselor agent's attire and its virtual environment. Our studies demonstrate that virtual agents dressed to fit their health care role are perceived to be more professional, trustworthy, reassuring, and more persuasive regarding medical decisions, compared to agents whose appearance is not role-appropriate. Furthermore, the effect of an agent's attire is greater than that of its virtual environment. The results of this research can help create visual guidelines for the development of virtual agents in tasks that rely on user trust.