Patterns of problem-solving activity in one middle-class urban high school are examined and a problem solving model rooted in a conceptual framework of contingency theory is presented. Contingency theory stresses that as political, economic, and social conditions in an organization's environment become problematic, the internal structures of the organization must be modified to meet the changing demands. In the case analysis, schools are viewed as networks of interlacing cycles of events dependent upon student and teacher behavioral cycles and upon environmental needs. Researchers, who acted as participant observers, gathered data over six months. They cooperated with school staff in a participatory way, yet were also impartial, confidential onlookers and questioners. The contingency theory model identifies problem solving as a cyclical process with the following seven key stages: problem recognition, problem screening, problem distribution, decision making, decision implementation, feedback, and problem resolution. Findings of this study indicate that problem solving at high schools can be identified as a cyclical process with several key stages. At each stage forces converge on the problem which determine the course of events leading to the subsequent stage and finally lead to the ultimate resolution of the problem. The conclusion is that a similar cyclical process with similar stages would be found in other schools if a contingency theory perspective was used. Ten propositions on problem solving are offered for further testing in other settings. (Author/DB)