A clinical data system is under development at the Upjohn Company that will reduce the time lag from patient visit to data availability, data entry errors, and the amount of training required for system use. The system design allows generality for both the study monitor and the biostatistician, editing of the data before entry, simplified forms design, direct entry of textual responses without coding, and a reduced need for special programs. Interactive subsystems allow a user to describe a study to the system, generate tailor-made entry/edit programs for each study, undate the date base, and produce ad hoc reports. The system is being implemented on top of a data base management system and runs on an IBM 370/148 under VM/CMS.