Past research has demonstrated that common ground is essential for effective verbal and non-verbal communication. In remote communication, establishing incremental common ground—that is, a common ground constructed by the flow of conversation—might be difficult because the speaker cannot sufficiently monitor the listener’s attentional cues. Therefore, in this study, we asked participants to do a route direction task via the remote meeting tool Zoom to investigate the effect of two types of common ground—personal common ground (shared knowledge between speaker and listener) and incremental common ground (shared knowledge through ongoing conversation). We counted the participants’ use of demonstratives (kore, sore, etc.) and gestures (iconic gesture and pointing), as these elements are important for grounding in conversation. Participants produced the greatest number of gestures when both personal and incremental common grounds were firmly established. When a personal common ground was well-established, participants used demonstratives more frequently if the incremental common ground was also firm. The findings suggest that both personal and incremental common grounds influenced participants’ use of gestures and demonstratives, indicating that common ground is essential for online communication.
