Based on observations of Army Group, corps, and division command posts in action over 12 different exercises and on interviews with a variety of military experts (including doctrine writers and former commanders), this report discusses the information needs of commanders of higher-echelon Army units. The authors attempted to determine the reasons commanders and staff communicated information and to clarify the intended uses of that information. They identified three different modes of command-post-level communication — pipeline, alarm, and tree. Each mode is indicative of a different communication relationship between a commander and his staff, and each places different demands on the command-and-control operating system. To fulfill commanders’ information needs, the authors recommend a number of education and training measures: (1) institutionalize back-briefing, (2) teach process as well as procedures, and (3) train unit command staffs to share images. As for the design of information systems, they recommend that the Army (1) identify means of more direct image sharing, (2) build a hybrid information system, and (3) establish an end-user to end-user communications orientation. Originally written in 1989, the information remains timely and useful; new edition includes a foreword by General Gordon Sullivan (USA-Ret.).