In Luther Gulick’s classic essay “Notes on the Theory of Organization,” he argued that span of control structures relationships between leaders and subordinates in organizations. Commenting on the state of knowledge about span of control, Gulick lamented the lack of systematic research on what he viewed as three key determinants of span of control: diversification of function, time, and space. This study adopts Gulick’s approach to studying span of control by examining the effects of diversity of function, time, and space in structuring relationships among personnel in a sample of 678 Texas public school districts. We then investigate Joan Woodward’s link between span of control and organizational performance. Our results reveal that although Gulick was correct in asserting that diversity of function, time, and space play a role in determining how spans of control are structured, these variables have different meanings that depend on the level of organizational hierarchy analyzed.