This report presents a description of the jobs of principals in a national sample of schools, summarizing the main results of a job analysis accomplished by using a structured task analysis inventory. It summarizes what principals in schools of different kinds report to be the most important aspects of their jobs. Results imply that principals are primarily supervisors of other personnel and that staff direction and observation and feedback of information about staff performance are the paramount job functions. Principals in schools of all types also have important roles in assessing school needs and planning for school improvement. Other results imply that the jobs of principals in public schools involve more interaction with higher levels of authority than do the jobs of principals in private schools. In contrast to public school principals, principals in private and Catholic schools may have more scope to make personnel and other administrative decisions and hence view these aspects of their jobs as more important than their public school counterparts. Differences among the jobs of principals in elementary, middle/junior, and high schools are described, as are differences in schools of different sizes. Differences associated with location (urban, suburban, rural) were usually not large or particularly meaningful. Implications of the job analysis for training and performance measurement are discussed. (Author/TE)