This paper reports on a study of the administrative behavior of school principals made through direct observation and a set of unique categories. Study objectives were to describe (1) the sources of principals' problems, (2) the principals' initial reactions to problem stimuli, (3) the patterns of principals' decisionmaking, (4) the premises employed by principals in making initial responses to problems, and (5) a tested system of categories for use by other researchers in studying administrators' decisionmaking behavior. Study results showed that principals' decisionmaking patterns are reactive, rapid, and probably strongly influenced by subordinates. (Author/LLR)