In text-based computer-mediated communication (CMC), people's language use and task performance can be affected by whether explicit coordination devices (e.g., a turn marker) are available. Analyses of 37 dialogues that emerged in text-based, CMC environments support Clark's (1996, 1997) proposal that a communication setting that disrupts the regulation of turn-taking will both undermine higher level language processes (i.e., the construal of meaning) and increase the frequency of metacommunicative signals required to coordinate the speaker's action with the listener's attention. The results indicate that the availability of a simple, explicit turn marker in a task-oriented, text-based exchange facilitates the construal of meaning and reduces the number of verbal coordination devices required to ground communication. Measures examining alternative interpretations indicate that these effects are not easily explained by differences in volubility or speed-accuracy trade-off across the 2 conditions.