The framework for public school social workers offered in this article is based on the systems approach. The ideas presented might also be useful to social workers in general, and to secondary school social workers in particular. The article deals with the idea of a boundary, which is a line forming a circle around selected variables. Interrelationships between variables within the system and outside it can be examined, and appropriate interventions developed on this basis. The distribution of power (ability to influence the beliefs and behaviors of others in accordance with a wish or plan) within the system must also be considered. Communications systems are discussed; they have implications for the social worker's knowledge of his own role and the organization of his school or agency. The framework attempts to systematize the social worker's thinking and help him or her to intervene decisively and effectively. (Author/BP)