At this stage in the development of diagnosis-related groups (DRG's), there is an imperfect record of the value and amount of nursing resources used by individual patients during a single hospital stay. Previous attempts to isolate the costs of nursing care in relationship to DRG's are reviewed. A research strategy to attain such relative measurements is proposed. Such inquiries are necessary if precise measurements of the relative contribution of nursing to each DRG are to be isolated, if new managerial models are to be isolated, if new managerial models are to be developed, and if objective measurements of severity within DRG's are to be devised.