To Physically Embody or Not? A Comparison of Virtual vs. Physical Robots as Exercise Coaches for Older Adults

As social robots gain prominence in supporting older adults’ health and well-being, understanding their effectiveness compared to virtual agents remains critical. This study investigated older adults’ perceptions of a physically embodied robot versus its virtual counterpart when taking on the role of an exercise coach. We recruited 25 healthy older adults, each of whom performed a series of exercises with both the physical NAO robot and its virtual simulation displayed on a computer screen. Participants’ experiences were assessed using the Unified Theory of Acceptance and Use of Technology (UTAUT) and the User Engagement Scale (UES) questionnaires collected after each condition. Results indicated that the Perceived Sociability of the NAO robot was significantly higher in the physically embodied condition compared to the virtual condition. However, no significant differences were found in Anxiety, Attitude, Perceived Enjoyment, Perceived Usefulness, Social Intelligence, or Trust. Similarly, the physically embodied NAO scored higher in Perceived Usability and Aesthetic Elements, but no significant differences were observed in Focused Attention and Reward Factor. These results suggest that physical embodiment could enhance perceptions of sociability and usability, however, it does not necessarily impact all engagement-related factors. Our findings contribute to the design of future socially assistive technologies in eldercare.