The present work investigated effects of mobility constraints on gesturing and other aspects of conversational engagement when using mobile technology. Based on studies of non-verbal communication and interaction quality, we compared mobile and static forms of video call in structured interviews. Using real-time motion capture and content coding of recordings as well as self-reports, several data sources were considered: hand velocity as an indicator of gesturing, observed levels of engagement and remembered conversational content. Gesturing, in contrast to other indicators of engagement, was reduced under high mobility constraints and was more pronounced under low constraints. Gesturing was further positively related to observed engagement. Additionally, lower constraints resulted in more memories of conversational content. These findings emphasise the relevance of mobility constraints and bodily movement during mediated interaction and call for further model development in computer-mediated communication. Potential for application lies in interactive scenarios such as remote interviewing, testimonials, and relationship maintenance.

Introduction

Imagine somebody in a busy inner city district walking at a swift pace, conversing all the while in a raised voice over mobile video call. Imagine the same person in a quiet room sitting at a table conversing over video call on a static computer screen. These examples reflect the simple and observable fact that more and more of our critical conversations, work and personal, are computer-mediated. With the rise of high-bandwidth communication networks and mobile technologies, the use of video calls has become wide-spread. To illustrate these trends, in 2017, the popular video call application Skype passed one billion downloads (The Skype Team, 2017) while Facebook’s Messenger recorded 17 billion video call episodes globally (Facebook, 2017). Global statistics, however, speak little of the actual set-up of devices and environments in which video calls are placed. The focus of the present work is on how conversations and their outcomes differ depending on the physical constraints device use puts on the conversation partners. Whereas the medium, and the technical requirements, are highly similar in the two opening examples, the physical constraints are not, and the level of movement involved is unlikely to be the same. A device that is kept stationary on a table, or a webcam in a static position, is likely to fix the speaker in a seated position. In contrast, a device that is held in hand allows conversations in a wide range of settings and body positions. Associations between movement, in the sense of bodily activation and physical motion, and the readiness to respond socially can be found frequently in such activities as dancing, hiking, exercising, or performing. At present, however, there is little theory to account for such differences in the field of computer-mediated communication. This may be due to a mis-match between established approaches to computer-mediated communication and the current spread of mobile communication technologies and the resulting spectrum of mobility constraints.