This paper presents findings of a study that utilized Elliott Jaques' theories of organizational depth structure and time span of discretion in administrative work to examine administrators' responsibilities in two Ontario (Canada) school systems. The theory predicts that the time-span of discretion associated with the administrative tasks will increase with the hierarchical rank of incumbents. Specifically, the study examined the effects of organizational size and enrollment (measures of school size) on administrators' time span discretion. The pilot study was conducted in two medium-sized school systems in Ontario. Interviews were conducted with a total of 38 participants--the principals and vice-principals at eight selected schools (two elementary and two secondary in each system), the district director (CEO), and all supervisory officers. Both superintendents and principals were found to be working at or close to the 2-year time-span level, with the directors of both systems engaging in work with a maximum time span of 3 years. Clearer hierarchical distinctions were evident in the work of vice-principals and department heads. These findings imply that the administrative responsibilities of principals are of equal weight and complexity to those of assistant superintendents, and thus the formal subordination of the former to the latter may be nonrequisite. Findings also indicate that school size, rather than school type, may be a more powerful determinant of the level of principals' administrative work. Overall, enrollment may serve as the best measure of a school's organizational size; however, the total number of employees is a more appropriate measure of organizational size for school systems. Five figures and four tables are included. (Contains 96 references.) (LMI)