A method for analyzing work of health personnel was devised and applied in a physical therapy service. Procedures for developing the special language for describing the tasks performed by physical therapists and methods for training observers to prepare sequential reports of the ongoing work of staff are presented. Observers were able to reliably report the detailed characteristics of the tasks in a physical therapy service over an extended period of time. Implications of the method are discussed.Personnel utilization studies of health and rehabilitation services are urgently needed since the gap between the supply and demand of fully qualified persons has not been narrowing. The Health Manpower Report (National Center for Health Statistics, 1968) revealed, for example, that 59% more physical therapists and 23% more physical therapy assistants were needed to meet the demand for services in 1968. In this light, therefore, it appears necessary to plan for the redistribution of the functions and responsibilities of physical therapists and other health professions to achieve maximum efficiency in training and utilizing all levels of personnel including assistants and aides. While the methodology described in the following pages was 1 The complete version of the results and instruments will soon be available in the