In this two-part paper, an attempt is made to examine the relationship between social contexts and effective schools and specifically to contribute to the development of a conceptual model for understanding how social contexts influence the operation of effective schools and student learning. In the first part, school effects research is drawn upon in order to elaborate upon a model developed by John Carroll (1963) at Teachers College. In the second part, the focus is on one set of relationships within Carroll's model in an attempt to broaden understanding of how social contexts influence the operation of instructionally effective schools. Research suggests that schools can become effective without parent involvement, yet parent involvement and expectations seem to have potentially powerful effects on student learning. It also raises the following question for future investigation: What combinations of effectiveness factors appear to enhance instructional effectiveness given varying social contexts? It is recommended that future studies examine both the source of expectations and the manner in which schools translate and communicate expectations to students. In particular, researchers should examine the principal's role in linking the school and the community. Contingency theories of organizational leadership may provide guidance in comceptualizing the dynamics between organizational context and effective instructional leadership behavior. (JAM)