Physical presence increases both presence and risk
Aliases: physical co-presence · embodied presence · robot social presence
What it is
Physical co-presence means that a person and a robot share a location, scale, and action space. Real distance, orientation, and motion can make the robot easier to interpret and more socially consequential. The same condition also lets it block a route, enter personal space, or make contact. Presence and risk are coupled consequences of sharing physical space, not two unrelated product qualities.
Why it happens
An embodied robot supplies depth, sound, airflow, vibration, and spatial-occupancy cues that a flat display attenuates. People also apply interpersonal spacing and yielding conventions to an apparently intentional mover. Yet shorter distance reduces available response time, while mass and momentum prevent instantaneous reversal. Socially engaging behaviours such as approaching, facing, and following therefore increase both the salience of the encounter and exposure to control or perception errors.
Studying it
Studies can hold task and functionality constant while comparing a physical robot with a life-size video or remote display. Relevant outcomes include social-presence ratings, trust, interpersonal distance, avoidance trajectories, startle responses, and task performance. Speed, closest approach, sound level, room geometry, and novelty need to be recorded because they can masquerade as an embodiment effect. Approach studies should report actual motion parameters and enforce a predefined stop boundary.
Where it stops holding
Physical presence does not guarantee a positive encounter. Children, mobility-impaired users, people with traumatic experiences, and robot-naive bystanders may interpret the same approach as threatening. A fixed, separated, or unpowered body can produce presence without the collision profile of a mobile platform. Conversely, mediated encounters can still produce substantial social presence, so embodiment should not absorb every difference between conditions.
Applying it
- Couple every presence-enhancing approach, follow, or facing behaviour to explicit speed, separation, and escape-path constraints.
- Let a person enlarge the distance by pausing, stepping back, or issuing a clear command, and make the robot's deceleration immediately legible.
- Test in the target space with varied body heights, mobility, and prior exposure. Use trajectories to inspect closest approach and avoidance, then use interviews to separate discomfort caused by distance, speed, or social meaning.