From its inception in the 1960s, the major focus of large-scale quantitative investigations of school effects has been on the issue of equal opportunities in education for disadvantaged and minority students. For two decades, school effects research attempted to identify the best way to deploy new federal resources for advancing educational equity. Beginning with the publication of the Equality of Educational Opportunity Report by James Coleman and others in 1966, this type of research was based on two different (but not inconsistent) conceptual frameworks. One, with an economic orientation, focused on school effectiveness as a series of input-output analyses (i.e., production functions) that were meant to estimate the impact of such fiscal resources as average teachers' salaries, books in the library, and class size on the average achievement of students in particular schools. Another strand, involving mainly sociologists, pursued issues of social stratification. Work using this second framework examined the role of education in status attainment. With years of schooling as the key independent variable, the primary focus was on the consequences of schooling for occupational and social mobility. 1 Both strands of school effects research in its early manifestation were conceptualized with a functionalist orientation based on human capital theory. Although seeking answers to ostensibly different questions, these two streams of work shared a common viewpoint: They conceived the organizational structure of a school as a "black box." As such, the in-