EFFECTIVE health facility planning requires that pertinent data be assembled at the time and place appropriate for consideration. We know these data to be ever expanding in mass and complexity, a development which not only accentuates the importance of the requirement, but makes it increasingly difficult to satisfy. To a growing number of people in the public health field, the most likely means of dealing with the dilemma is a computer-based information system. Only such a system, it appears, is capable of performing necessary information linkages and completing complicated operations within time limitations that are meaningful. In California, the need for improved data led the State Department of Public Health, Bureau of Hospitals, to initiate a demonstration project aimed at developing a system able to serve the needs of health facilities planning. (The bureau has since been reorganized as part of the new Division of Patient Care Facilities and Services.) This project is known as CHIPS-California Health Information for Planning Service. It operates under the United States Public Health Service Grant HM-00446 with a starting date of June 15, 1965, and is funded through May -31, 1968.*