This study examines the effects of text-based computer-mediated commun
ication on group interaction. Fourteen four-person teams were trained
to use a networked computer system to produce a sequence of written re
ports either face-to-face (FTF), or from separate locations using a co
mputer-mediated communication (CMC) system. Results showed that CMC te
ams took longer to complete their work, but produced reports of equiva
lent quality to FTF teams. Comparisons of interaction processes reveal
ed a shortfall of social-emotional reactions and task-oriented request
s in CMC interactions, but an increase in ingroup-oriented exchanges.
Results are interpreted as evidence of a messaging threshold in CMC, i
n which the decision to send a message depends on the urgency and rele
vance of the message in relation to the costs associated with its comm
unication. Implications of this threshold for understanding social int
eraction in CMC groups are discussed.