In most situations, communication among parties involved in a group problem-solving situation is regarded as desirable if not essential, since each member's intentions can be made known and future actions made predictable. The present experiment was designed to test the hypothesis that communication facilitates the development of effective and predictable structure-in-interaction and thus contributes to the effectiveness of the group's problem-solving activities. Data analysis suggests that under certain conditions group task performance may be hindered rather than facilitated by communication. This result was not anticipated.