Physically Present or Virtually Represented: A Meta-Analysis of Robot Representation Type’s Impact on Acceptance in Human-Robot Interaction.

The validity of using non-physically co-located (NPC) robots versus physically co-located (PC) robots in human-robot interaction research remains debated, with mixed empirical findings threatening study reliability and theoretical frameworks. This systematic review and meta-analysis examined whether robot interaction modality significantly affects human acceptance by analyzing 30 studies representing 1,944 participants across eight acceptance sub-dimensions. Using psychometric meta-analytic methods with corrections for sampling error and measurement unreliability, we found no significant overall effect of robot representation type on acceptance (r² = 0.07, 95% CI: -0.02, 0.16, k = 25). Non-significant effects emerged across acceptance sub-dimensions including attitude, trust, social presence, intention to use, perceived enjoyment, anxiety, and actual use, with effect sizes ranging from -0.13 to 0.16. Moderator analyses examining representation type (screen-based versus virtual reality), contextual factors (field of application, human role), and measurement type (objective versus subjective) failed to explain the moderate to high heterogeneity observed across studies. Publication bias assessment revealed relative symmetry, and risk of bias evaluation indicated moderate robustness across included studies. These findings challenge the embodiment hypothesis in human-robot interaction, suggesting physical co-presence may not provide presumed advantages over virtual representations, and support investigating when rather than if differences between robot modalities emerge.