The third of four volumes in Research Report No. 7 of the Health Services Mobility Study (HSMS), this book contains 149 diagnostic radiologist task descriptions that cover activities in the area of nursing (patient care), film processing, quality assurance, radiation protection, machine maintenance, housekeeping, and administration at the departmental level. (The medical activities of radiologists are covered in Volume 1 and the patient procedures of radiologic technologists are covered in Volume 2. The first three volumes present the tasks in a given area in numerical order by code number. Volume 4 is an index of all the tasks in the three volumes.) These task descriptions are offered for use as instructional materials, as inputs to the design of career ladders, for the structuring of jobs and assignment of work to job titles, and as inputs to the development of performance evaluation instruments and proficiency tests. Chapter I of this volume defines "tasks" and tells how the descriptions were developed. The task descriptions are presented in numerical order by code number in Chapter 3 where the steps of the task are described in logical sequence in considerable detail. Chapter 2 is a guide to the tasks arranged in logical groupings (1) by function, such as patient care, quality assurance, radiation protection; and (2) by type of recipient, such as patient or co-worker. (HD)