Group tasks require communication, but communication can be excessive and time-wasting. The authors develop propositions group productivity and interaction. High reciprocal interdependence in teams requires high levels of interaction, but when interdependence is low, interaction can interfere with productivity. After developing appropriate measures of the variables, they tested that idea and related ideas with 224 R & D teams and found a strong relationship between communication and productivity on interdependent tasks.This research was supported by the Division of Industrial Science and Technological Innovation of the National Science Foundation under grant #IS1-8304340