1. Introduction
Socially Assistive Robotics (SAR) has referred to robotics that assisted people with physical or
cognitive disabilities through mutual interaction. SAR technology enables monitoring, motivating, and
coaching people with disabilities in various ways [1]. As motivation is considered as one of the most
significant factors in SAR, many researchers have explored the impact of SAR on motivation. For
example, Tapus et al. applied a robot on motivating elders with dementia [2].
As social presence has an effect on motivation [3], we focused on the impact of the robot types by
human intervention levels, which could be related to social presence. According to the human
intervention levels in controlling a robot, robots could be categorized into an autonomous robot and a
tele-operated robot. An autonomous robot which has low human intervention level elicits the fabricated
artificial social presence while a tele-operated robot which has high human intervention level delivers
the social presence of a real person. Previous studies have been done on the impact of human
intervention levels of a robot on people’s perception of a robot, such as feelings of empathy [4] and
being secured [5]. Even though various studies have been done on the impact of the robot types on
emotional engagement between a person and a robot, limited work has been done on motivation in
physical exercise, such as physical rehabilitation, physical exercise training, and etc. Thus, in this study,
we investigated the impact of the robot types regarding human intervention levels on people’s
motivation in physical exercise.
2. Related works
2.1. Human Intervention Levels of a Robot
Robots could be classified into an autonomous robot and a tele-operated robot according to the
degrees of human intervention, which is required for controlling a robot [6]. An autonomous robot is an
independent social actor, which delivers its status by itself. On the other hand, a tele-operated robot is a
pure medium, which delivers a remote operator’s status to a receiver. Thus, an autonomous robot is
having low human intervention level whereas a tele-operated robot is having high human intervention
level [6].